Therapeutic delivery vesicles

ABSTRACT

The present invention pertains to inter alia methods for purifying extracellular vesicles including exposing a sample comprising at least one extracellular vesicle to ultrafiltration; and exposing the sample following the ultrafiltration in step (i) to size exclusion liquid chromatography.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/795,429, filed on Feb. 19, 2020, which is a divisional of U.S.application Ser. No. 14/784,015, filed on Oct. 12, 2015, now U.S. Pat.No. 11,274,139, which is a national stage application filed under 35U.S.C. § 371, of International Application No. PCT/SE2014/000047, filedApr. 10, 2014, which claims priority to Sweden Patent Application No.1300271-2, filed Apr. 12, 2013. The contents of each of theaforementioned patent applications are incorporated herein by referencein their entireties.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted in .xml format via electronic submission and is herebyincorporated by reference in its entirety. Said .xml document wascreated on Dec. 12, 2022 is named “EVOX-001_SeqList_ST26.xml” and is267,369 bytes in size.

TECHNICAL FIELD

The present invention pertains, inter alia, to therapeutic deliveryvesicles, for instance exosomes or microvesicles, comprising polypeptideconstructs, methods for producing said therapeutic delivery vesicles,pharmaceutical compositions and medical uses thereof.

BACKGROUND ART

Exosomes and microvesicles are membrane-bound vesicles that differ basedon their process of biogenesis and biophysical properties, includingsize and surface protein markers. Exosomes are homogenous smallparticles ranging from 40 to 150 nm in size and they are normallyderived from the endocytic recycling pathway. In endocytosis, endocyticvesicles form at the plasma membrane and fuse to form early endosomes.These mature and become late endosomes where intraluminal vesicles budoff into an intra-vesicular lumen. Instead of fusing with the lysosome,these multivesicular bodies directly fuse with the plasma membrane andrelease exosomes into the extracellular space. Exosome biogenesis,protein cargo sorting, and release involve the endosomal sorting complexrequired for transport (ESCRT complex) and other associated proteinssuch as Alix and Tsg101.

In contrast, another type of extracellular vesicles, namelymicrovesicles, are produced directly through the outward budding andfission of membrane vesicles from the plasma membrane, and hence, theirsurface markers are largely dependent on the composition of the membraneof origin. Further, they tend to constitute a larger and moreheterogeneous population of extracellular vesicles, ranging from 150 to1000 nm in diameter. However, both types of vesicles have been shown todeliver functional mRNA, miRNA and proteins to recipient cells.

To maintain a physiological balance in receptor signalling and responseseveral receptors exists both in a membrane bound form and in a solubleform. The membrane form is normally capable of signalling, whereas thesoluble form is signalling-incompetent. The soluble form often occurs asthe extracellular part of the membrane-bound form. The soluble part isgenerated in two different ways: (1) alternative splicing of thepre-mRNA, and (2) by cleavage of extracellular proteases (oftenmetalloproteases). The soluble form binds its ligand and therebysequesters the ligand, inhibiting its binding with the membrane-boundform, meaning that the overall signalling from that pathway willdecrease. The soluble form often increases when the signalling pathwayis very active. For instance, the soluble forms of the two tumournecrosis factor receptor alpha (TNFRαs) increase in pathologicalconditions such as sepsis and inflammation in order to reduce theinflammatory process.

Decoy receptors have received substantial interest from a therapeuticpoint of view, since they provide a highly specific and tailoredapproach to decrease the physiological concentration of a protein ofinterest. The therapeutic modality is reliant on administration of decoyreceptors in order to decrease the activity of a particular signalingpathway. Decoy receptors are often fused with the Fc-part of an antibodyto increase their half-life and to increase the avidity of the receptorswhen two come in close range from each other. One example of thisstrategy is Etanercept, which is the sTNFR2 fused with an Fc-fragment.Etanercept is clinically approved for treating rheumatoid arthritis,psoriatic arthritis, ankylosing spondylitis and moderately to severelyactive polyarticular juvenile idiopathic arthritis, and it has beenshown to be safe and effective over the last 19 years since its initialapproval. Several other decoy receptor fusion proteins are in clinicaltrials, targeting for example VEGF, EGF, FGF and angiopoietin.

Although successfully applied in various therapeutic contexts and for alarge number of ailments, decoy receptors and other biologics(biopharmaceuticals) suffer from a number of drawbacks relating to forinstance pharmacokinetics, toxicity, pharmacodynamics, and therapeuticefficacy.

SUMMARY OF THE INVENTION

It is hence an object of the present invention to overcome theabove-identified problems associated with the use of biologics, andspecifically decoy receptors, and to satisfy the existing needs withinthe art, namely to provide for optimized therapeutic efficacy,significantly improved pharmacokinetics, as well as reduced side-effectsof biopharmaceutical polypeptides, such as decoy receptors and biologics(biopharmaceuticals) in general.

Thus, the present invention pertains to, in a first aspect, atherapeutic delivery vesicle having attached to its membrane apolypeptide construct, wherein the polypeptide construct comprises atleast one carrier polypeptide fused to at least one therapeuticpolypeptide decoy receptor present at least partially on the outside ofthe delivery vesicle, and wherein the at least one therapeuticpolypeptide decoy receptor is signalling-incompetent, i.e not capable oftransmitting signals it transmits under normal circumstances. Normallythe decoy receptor binds to and sequesters a circulating ligand or aligand that may in fact also be present inside a target cell and/or onthe surface of a target cell. Without wishing to be bound by any theory,it is surmised that therapeutic polypeptide decoy receptor present onthe surface of therapeutic delivery vesicle sequesters its interactionpartner(s), i.e. the target and/or ligand, in virtually the same manneras the free therapeutic polypeptide decoy receptor, albeit with asignificantly improved half-life, reduced clearance, decreasedside-effects, and generally significantly enhanced pharmacokinetics, andtherapeutic efficacy, by virtue of its attachment on a suitable deliveryvesicle, for instance an exosome, a microvesicle, an apoptotic body, aliposome, or any other type of naturally derived or artificiallyproduced vesicle. The at least one therapeutic polypeptide decoyreceptor present on the therapeutic delivery vesicle may be partially orcompletely devoid of its signalling domain, so as to make it asignalling-incompetent therapeutic polypeptide receptor, and thesignalling domain may be partially or completely replaced by the carrierpolypeptide, but the incapacity to contribute to signalling may alsoderive from alterations in the polypeptide sequence. For instance, invarious embodiments of the present invention it may be sufficient toreplace certain amino acids to render the therapeutic polypeptidereceptor signalling-incompetent, and/or the therapeutic polypeptidereceptor may be rendered signalling-incompetent merely by attaching thedecoy receptor to the carrier polypeptide (using recombinant technology)which is transporting the entire polypeptide construct to the surface ofthe extracellular vesicle.

Importantly, exosomes and other types of cell-derived vesicles (whichconstitute a conceivable source of delivery vesicles in accordance withthe present invention) may have therapeutic activities per se. Forexample, vesicles derived from e.g. mesenchymal stem cells but also fromother cells are known to be innately immunosuppressive as they carryseveral miRNAs, proteins and bioactive lipids that for instance suppresscytotoxic T-cells and trigger expansion of regulatory T-cells. Therepressive effect on the immune system is a prerequisite also forsubsequent tissue regeneration following tissue injury. Hence, choosingfor instance an appropriate source of cells for derivation of exosomesand/or other types of extracellular vesicles will provide an additionaltherapeutic advantage as compared to using receptor decoys/monoclonalantibodies (such as etanercept and infliximab) only.

In further aspects, the instant invention relates to therapeuticdelivery vesicles and pharmaceutical compositions comprising thevesicles in accordance with the present invention for use in medicine,and more specifically for use in the treatment, alleviation, and/orprophylaxis of various diseases and disorders that may be treated usingbiopharmaceutical therapeutics (biologics).

Thus, the present invention essentially pertains to the use of exosomesand other vesicles (notably derivable from cellular and/or biologicalsources, but alternatively also artificially produced vesicles such asliposomes) as delivery or administration vehicles forbiopharmaceuticals, specifically polypeptide-based biologics, and morespecifically decoy receptors (also known as sink receptors). The presentinvention hence relates to the use of exosomes (and other types ofvesicles) comprising various polypeptides, as defined herein, in thetreatment of a large number of diseases and disorders, as hereindisclosed.

In additional aspects, the instant invention pertains to methods ofproducing the therapeutic delivery vesicles of the present invention,generally comprising the steps of (i) providing at least onepolynucleotide construct encoding at least one therapeutic polypeptidedecoy receptor (which is preferably signalling-incompetent, for instancevia being partially or completely devoid of its signalling domain) thatbinds to a suitable target and/or ligand, (ii) introducing said at leastone polynucleotide construct into a cell capable of producing exosomes,and, (iii) collecting (harvesting) at least one delivery vesicleproduced by the cell of step (ii). The present invention also relates todelivery vesicles produced by said methods, as well as various aspectsand embodiments related to kits, compositions, and cell culture media inaccordance with the present invention.

In further aspects, the present invention relates to methods forincreasing the yield of extracellular vesicles (which may be in theirnative form, i.e. completely free from therapeutic polypeptideconstructs) comprising exposing the cells (which are the source of theextracellular vesicles) to inhibitors of autophagy. In yet a furtheraspect, the present invention pertains to methods for increasing theregenerative capacity of extracellular vesicles, by exposing the cellsource to stress-inducing conditions (for instance oxygen deprivationand/or serum starvation). Exposure of vesicle-producing cells tostress-inducing conditions results in enrichment of metabolically activeproteins and/or anti-apoptotic proteins, which leads to enhancedregenerative effects.

The present invention thus provides delivery vesicles, methods,compositions, and uses, as well as various other aspects andembodiments, for improving the delivery, administration, andcharacteristics of e.g. biopharmaceutical polypeptide agents. Thepresent invention results in optimized therapeutic efficacy (forinstance due to therapeutic polypeptide decoy receptor multivalency andthe inherent regenerative therapeutic effects of exosomes per se),significantly improved pharmacokinetics (via e.g. reduced renalclearance), improved biodistribution to certain organs, such as thebrain, as well as reduced side-effects of biopharmaceutical polypeptides(via e.g. fusion with recipient cells to confer direct cellularprotection), such as decoy receptors and other types of biologics.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows treatment efficacy, in a mouse colitis model, of exosomescomprising a signalling-incompetent therapeutic polypeptide decoyreceptor, which is comprised of a signalling-incompetent soluble tumournecrosis factor receptor 1 (sTNFR1) (which may be either one of sTNFR 1A(SEQ ID No 30) or sTNFR 1B (SEQ ID No 31)), fused to the carrierpolypeptide CD63 (SEQ ID No 14). The exosomes displayingsignalling-incompetent sTNFR1-CD63 successfully treat the inducedcolitis (solid black line) with only a minor initial loss in bodyweight. Signalling-competent exosomes (short-dashed grey line) showclear anti-therapeutic efficacy since they deliver more signallingreceptors to the cells, whereas mock-treated mice (dotted line) did notdisplay any clinically relevant efficacy. Unmodified exosomes (i.e.exosomes devoid of any artificially introduced polypeptide constructs)(long-dashed grey line) also induced moderate colitis remission,probably due to their inherent anti-inflammatory effects.

FIG. 2 shows Western blot confirmation of the presence, on the exosomalsurface, of the CD63-sTNFR1 polypeptide used for the colitis treatmentof FIG. 1 .

FIG. 3 shows the neutralizing activity of the sTNFR1 decoy exosomes ofFIG. 1 on TNFα-mediated cytotoxicity. The exosomes displayingsignalling-incompetent sTNFR1-CD63 exhibit good TNFα neutralization in adose-dependent manner (solid black line), and the signalling-competentsTNFR1-CD63-containing exosomes are, as in FIG. 1 , aggravating theresponse (short-dashed grey line). Unmodified exosomes (long-dashed greyline) also show a moderate effect due to their anti-inflammatoryproperties.

FIG. 4 shows a graph over the tumour inhibitory effects of exosomesdisplaying either signalling-incompetent soluble vascular endothelialgrowth factor receptor (sVEGFR) (SEQ ID No 17) fused to CD63 (solidblack line) or signalling-incompetent sVEGFR fused to syndecan (SEQ IDNO 23-26) (dashed black line). Mice treated with exosomes comprising theabove polypeptide constructs had a considerably reduced tumour burdenpost treatment, whereas treatment with exosomes comprisingsignalling-competent sVEGFR polypeptide did again display a worsenedoutcome compared to control (short-dashed grey line).

FIG. 5 shows treatment efficacy in MDX mice of exosomes comprising thetherapeutic decoy polypeptide receptor activin (SEQ ID No 40-43) fusedto either the carrier proteins syndecan (solid black line) orsynaptotagmin (SEQ ID No 27) (long-dashed grey line). Bi-weeklytreatment with the above therapeutic delivery exosomes resulted in aconsiderably greater body weight increase than treatment with unmodifiedexosomes and mock treatment.

FIG. 6 shows the amino acid sequences of various polypeptide constructsas per the present invention. Some of the constructs comprise His tags(for facilitated purification) whereas others comprise EGFP (tofacilitate detection) but the constructs may naturally be applied bothwith and without said additional moieties/sequences.

FIG. 7 illustrates the increased therapeutic efficacy seen when usingexosomes (comprising a therapeutic polypeptide comprising soluble tumournecrosis factor receptor 1 (sTNFR1) fused to the carrier polypeptideCD63) obtained via ultrafiltration-liquid chromatography (UF-LC)purification (solid black line), compared to the same exosomes obtainedvia a conventional ultracentrifugation (UC) process (crossed solid blackline). The increased therapeutic efficacy is most likely due to theimproved biophysical stability of the exosomes obtained via UF-LC, whichin turn results in less accumulation in lung tissue.

FIG. 8 shows inhibition of autophagy resulting in increased exosomalyields. The graph displays, from left to right, cells treated withculture media only (as a baseline control), growth factor-supplementedmedia (for instance supplemented with IGF-1), media comprising autophagyinhibitors (3-methyladenine and bafilomycin) or media comprisingautophagy activators (rapamycin). Treatment with autophagy inhibitorsresults in a strong increase in the exosomal yield, which can beexploited in the production of exosomes as per the present invention.

FIG. 9 shows how EAE-mice treated with exosomes comprising displayingsignalling-incompetent therapeutic decoy receptors for IL6 (SEQ ID No1-2), IL-1β (SEQ ID No 3-5) and TNFα (solid black line and solid blacklines with circles, squares, and diamonds) display a very moderatedisease manifestation compared to mock treated control (dotted line),whereas signalling-competent (TNFR1 signalling-competent) exosomestreated mice in fact display a worsened disease (dashed grey line).

FIG. 10 illustrates the effects of stress-inducing conditions onenrichment of anti-apoptotic and metabolically active proteins,according to GO-terms (GO-terms: translation, metabolic processes,glycolysis and ribosomal proteins). As compared to cells cultured undernormal conditions, exosomes obtainable from cells cultured understress-inducing conditions (e.g. serum-starvation and/or oxygendeprivation) are enriched in proteins for survival and metabolicprocesses, which is beneficial for regenerative medicine applications.

DETAILED DESCRIPTION OF THE INVENTION

The present invention pertains inter alia to, in a first aspect, atherapeutic delivery vesicle having attached to its membrane apolypeptide construct, wherein the polypeptide construct comprises atleast one carrier polypeptide fused to at least one therapeuticpolypeptide decoy receptor present at least partially on the outside ofthe delivery vesicle, and wherein the at least one therapeuticpolypeptide decoy receptor binds to a circulating ligand. In furtheraspects, the instant invention relates to delivery vesicles andpharmaceutical compositions in accordance with the present invention foruse in medicine, as well as to methods of producing delivery vesicles,kits, compositions, and cell culture media.

Where features, embodiments, or aspects of the present invention aredescribed in terms of Markush groups, a person skilled in the art willrecognize that the invention is also thereby described in terms of anyindividual member or subgroup of members of the Markush group. Theperson skilled in the art will further recognize that the invention isalso thereby described in terms of any combination of individual membersor subgroups of members of Markush groups. Additionally, it should benoted that embodiments and features described in connection with one ofthe aspects and/or embodiments of the present invention also applymutatis mutandis to all the other aspects and/or embodiments of theinvention. For example, the at least one therapeutic polypeptide decoyreceptor described in connection with therapeutic delivery vesicles isto be understood to be potentially relevant/applicable/present also inthe context of the methods of producing delivery vesicles or in thecontext of the pharmaceutical compositions, or in connection with thepolypeptide and/or polynucleotide constructs as per the presentinvention. Furthermore, certain embodiments described in connection withcertain aspects, for instance the administration routes of thetherapeutic delivery vesicles, as described in relation to aspectspertaining to treating certain medical indications, may naturally alsobe relevant in connection with other aspects and/or embodiment such asaspects/embodiments pertaining to the pharmaceutical compositions of thepresent invention. As a general remark, the therapeutic polypeptidedecoy receptors and the carrier polypeptides in accordance with thepresent invention may be freely combined in any and all possiblecombinations without deviating from the scope and the gist of theinvention, and the sequences may deviate strongly from the originalsequences as long as any given carrier polypeptide retains its abilityto carry the therapeutic polypeptide decoy receptor to the surface of anextracellular vesicle, and as long as any given therapeutic polypeptidedecoy receptor retains its ability to bind to its target in atherapeutically efficacious manner. As long as their biologicalproperties are retained the polypeptide sequences may deviate with asmuch as 50% (calculated using for instance BLAST or ClustalW) ascompared to the native polypeptide, although a sequence identity that isas high as possible is preferable. The combination (fusion) of thecarrier and the decoy receptor polypeptides implies that certainsegments of the respective polypeptides may be replaced and/or modified,meaning that the deviation from the native sequence may be large as longas the key properties are conserved.

For convenience and clarity, certain terms employed herein are collectedand described below. Unless otherwise defined, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs.

The term “therapeutic delivery vesicle”, interchangeably termed“delivery vesicle”, shall be understood to relate to any type of vesiclethat is, for instance, obtainable from a cell, for instance amicrovesicle (any vesicle shedded from the plasma membrane of a cell),an exosome (any vesicle derived from the endo-lysosomal pathway), anapoptotic body (from apoptotic cells), a microparticle (which may bederived from e.g. platelets), an ectosome (derivable from e.g.neutrophiles and monocytes in serum), prostatosome (obtainable fromprostate cancer cells), cardiosomes (derivable from cardiac cells) etc.Furthermore, the terms “therapeutic delivery vesicle” and “deliveryvesicle” shall also be understood to potentially also relate tolipoprotein particles, such as LDL, VLDL, HDL and chylomicrons, as wellas liposomes, lipid-like particles, lipidoids, etc. Essentially, thepresent invention may relate to any type of lipid-based structure(vesicular or with any other type of suitable morphology) that can actas a delivery or transport vehicle for the therapeutics polypeptideconstruct(s).

The term “attached to its membrane” shall be understood as attached inthe sense of how a biological polypeptide is normally attached to avesicular membrane, i.e. predominantly via non-covalent interactions butpossibly also via covalent bonds. The attachment to the membrane maycomprise attachment inside the vesicle, in the vesicle membrane, on theoutside of the vesicle, or any combination thereof. A typical example ofa polypeptide being “attached” to the membrane of a vesicle is atransmembrane polypeptide that spans the bi-layer vesicular membrane ofan exosome from the intra-exosomal space out through the exosomalmembrane to the extra-exosomal milieu.

The term “polypeptide construct” (or interchangeably “therapeuticpolypeptide construct”) shall be understood to relate to any polypeptidethat comprises a “carrier polypeptide”, as defined herein, and a“therapeutic polypeptide decoy receptor”, as defined herein. Thepolypeptide construct may be attached to the membrane of the deliveryvesicle in accordance with the present invention, preferably in atransmembrane manner (i.e. with the polypeptide construct extending fromthe inside of the delivery vesicle, through the delivery vesiclemembrane, to the outside of the delivery vesicle). When the therapeuticpolypeptide decoy receptor is having a transmembrane configuration itmay be preferable if the carrier polypeptide is present substantially onthe inside of the delivery vesicle whereas the therapeutic polypeptidedecoy receptor is present at least partially on the outside of thedelivery vesicle, to be able to exert its therapeutic effect.

The term “signalling-incompetent” shall be understood as not capable oftransmitting biochemical signals, i.e. a polypeptide that issignalling-incompetent is merely binding its extracellular interactionpartner but upon binding no signals (i.e. no intracellular, nointravesicular, or no extracellular) are being generated or transmitted.For example, in the case of the soluble TNFR (sTNFR), even iftransferred to immune cells a signalling-incompetent TNFR cannot exert abiological response as it lacks crucial signalling components.Similarly, mimics of the EGFR (SEQ ID No 18) may lack the transmembranedomain which prohibits insertion into the membrane of recipient cells,thereby not being able to transmit biological signals, e.g. in the eventof a transfer to a recipient cell. Importantly in a clinical context, inthe case of TNFr, transfer a of signalling incompetent receptor torecipient cells offer another layer of protection as they then directlyprotect the cells from excessive TNF signalling by competing for ligandbinding. For clarity, both the therapeutic polypeptide decoy receptorand/or the entire polypeptide construct may be signalling-incompetent.For instance, the therapeutic polypeptide decoy receptor may be renderedsignalling-incompetent through e.g. a site-specific mutation, but asignalling-competent therapeutic polypeptide receptor may be madesignalling-incompetent through replacement of and/or attachment to itssignalling-domain by a carrier polypeptide.

The term “carrier polypeptide” shall be understood to relate to anypolypeptide that can be utilized to transport a polypeptide construct toa suitable vesicular location. More specifically, the term “carrierpolypeptide” shall be understood as comprising any polypeptide thatenables transporting or shuttling of a polypeptide construct (which said“carrier polypeptide” forms part of) to, at least partially, thevesicular membrane and, at least partially, the extra-vesicular side(for instance the surface) of a delivery vesicle in accordance with thepresent invention. Examples of carrier polypeptides are for instanceLamp2b (SEQ ID No 22), CD9 (SEQ ID No 12), CD81 (SEQ ID No 13), CD63,syndecan, ALIX (SEQ ID No 28), syntenin (SEQ ID No 29), andsynaptotagmin, but numerous other polypeptides capable of transporting apolypeptide construct at least partially to the extra-vesicular side ofdelivery vesicle are comprised within the scope of the presentinvention.

The terms “therapeutic polypeptide decoy receptor”, “polypeptide decoyreceptor”, and “decoy receptor” are used interchangeably herein andshall be understood to relate to any polypeptide (often called a decoyor a sink receptor) that can be utilized for therapeutic purposesthrough sequestering (binding) a suitable target and/or ligand (normallya circulating ligand or a ligand present on a cell that is itself incirculation but potentially any ligand on the surface of and/or inside atarget cell), thereby exerting its therapeutic effect. The decoyreceptor binds to and/or sequesters its target, which in essenceinhibits the target from carrying out its function which may contributeto a disease and/or disorder to be treated. The signal transductionprocesses of the major receptor classes are described in some detailbelow, to exemplify certain therapeutic polypeptide decoy receptors inaccordance with the present invention. However, as above-mentioned, thedecoy receptors of the present invention are preferablysignalling-incompetent, to ensure therapeutic efficacy and safety.

The terms “ligand” and “target” in the context of the present inventionshall be understood to comprise any molecule that is bound (normallywith high affinity, e.g. a Kd of less than 100 μM but preferably below 1μM or more preferably below 100 nM or even more preferably below 100 nM)by the therapeutic polypeptide decoy receptors according to the instantinvention. The ligand (which may be any polypeptide orcarbohydrate/polysaccharide or essentially any molecule, for instancepresent on the surface of a cell) is normally circulating freely in theblood or in any other bodily fluid (TNFα is an example of such a freelycirculating polypeptide ligand for the TNFα receptor) but it may also bea polypeptide or any other type of molecule present on a cell and/orinside a cell which circulates in a bodily fluid, for instance blood. Anexample of a cell-bound target may be CD19, which is present on acirculating B cells, and which can be bound by a therapeutic polypeptidereceptor such as the commercially available rituximab. The term “ligand”shall thus be understood to comprise both polypeptide andnon-polypeptide molecules (for instance carbohydrates or any other typeof molecule).

The phrase “binds to a ligand/target” shall be understood as thetherapeutic polypeptide decoy receptor having the capacity to bind to aligand and/or a target in the human and/or animal body, meaning that thedecoy receptor may bind to and sequester its ligand, to exert atherapeutic effect by inhibiting the ligand/target from carrying out itsnormal physiological function. The ligand/target is normally circulatingin the blood stream or is exposed to the extracellular environmentthrough being present on the surface of a target cell.

Signal transduction normally occurs in vivo when an extracellular ligandbinds to a cell surface receptor and activates it. In turn the receptorchanges intracellular proteins/molecules, which starts a signallingpathway. There are two main receptor groups; extracellular receptors andintracellular receptors. The extracellular receptors can be furtherdivided into different classes:

1. G-protein coupled (7-TM) receptors

2. Tyrosine and histidine kinases

3. Integrins

4. Toll gate receptors

5. Ligand-gated ion channel

7-TM receptors have 7 transmembrane regions and are linked to aheterotrimeric G-protein. Upon ligand binding the receptor undergoes aconformational change and the G-protein becomes active. The activated Gprotein subunits detaches from the receptor and initiate signaling viamany downstream effector proteins such as phospholipases and ionchannels. Adrenergic- and chemokine receptors belong to this family.7-TM receptors can be made signaling-incompetent by removing the bindingsite for the G-proteins. For instance, replacing the intracellularbinding site of G-proteins with the syntenin binding site of Syndecanswould direct a signaling-incompetent receptor to an exosome.

Tyrosine kinase receptors (RTKs) are transmembrane proteins with anintracellular kinase domain and an extracellular ligand-binding domain.Examples of ligands are growth factors, insulin, etc. To induce a signalthe RTKs need to form dimers at the plasma membrane. When a dimer isformed the interaction between the intracellular domains initiatesauto-phosphorylation of the tyrosine residues which causes aconformational change in the receptor. The kinase domains of thereceptors are subsequently activated and phosphorylate downstreamsignaling molecules that create a signaling cascade.

The tyrosine receptors can be made signaling-incompetent by removing ormutating the kinase domain or the tyrosine domain. This can be done in asimilar manner as with the 7-TM receptors. Further, the extracellulardomain of tyrosine receptors could be fused with an exosomal protein,such as CD63, Lamp2b, etc.

Integrins are transmembrane proteins that are important for cellattachment to other cells as well as to the extracellular matrix. Theintegrins also take part in the transduction of signals from theextracellular matrix proteins such as fibronectin and collagen.Integrins change their conformation upon ligand binding; integrins lacka kinase domain which means the integrins need adaptor molecules torelay the signal into the cell. There are several adaptor molecules andintegrin-linked kinases. The integrins can exist in two differentconformations: an inactive form and an active form. The inactive form iscommon on non-activated leucocytes; when the leucocytes are activatedthe cell changes its integrins to an active state. Integrins aresignaling incompetent without its adaptor molecules, so the bindingsites for the adaptor molecules and kinases can be removed to render thereceptors signaling-incompetent.

Toll-like receptors have four known adaptor molecules which areactivated upon ligand binding. This four adaptor molecules, Myd88,TIRAP, TRIF, and TRAM, subsequently activate intracellular molecules,and the Toll-like receptors inhibit or activates thousands of genes whenactivated. The Toll-like receptors can be made signaling-incompetentthrough removal of either the binding site and/or the interaction sitesfor the adaptor molecules.

The various polypeptides mentioned in the present application (forinstance carrier polypeptides such as Lamp2b or CD63, and therapeuticpolypeptide decoy receptors such as sTNFR or VEGFR, etc.) shall beunderstood to relate also to homologous polypeptides having sequenceidentities to the polypeptide in question preferably above 50%, morepreferably above 60%, more preferably above 70%, more preferably above80%, and more preferably above 90%.

In a first aspect, the present invention relates to a therapeuticdelivery vesicle having attached to its membrane a polypeptideconstruct, wherein the polypeptide construct comprises at least onecarrier polypeptide fused to at least one therapeutic polypeptide decoyreceptor present at least partially on the outside of the deliveryvesicle and wherein the at least one therapeutic polypeptide decoyreceptor is signalling-incompetent, to enable binding and sequesteringof its target molecule without the generation and/or transmission of anysignals. In a preferred embodiment, the at least one therapeuticpolypeptide decoy receptor binds to a circulating ligand but it maynaturally also bind to a target molecule present on a target cell. Thetherapeutic polypeptide construct may comprise at least one therapeuticpolypeptide decoy receptor (interchangeably termed a “decoy receptor”,but said therapeutic polypeptide decoy receptors may also relate totherapeutic polypeptides not necessarily classified as decoy receptorsas such) that is signalling-incompetent (or alternatively in someembodiments signalling-competent), fused to a carrier polypeptide.Naturally, one single delivery vesicle may comprise more than onepolypeptide construct (i.e. a plurality of constructs are present on asingle exosome), and also more than one type of polypeptide construct (asingle exosome could, for example, comprise a plurality of (1)constructs comprising the VEGF receptor, as the decoy receptor, and acarrier polypeptide, such as Lamp2b, and (2) constructs comprising theEGF receptor, as the decoy receptor, and the carrier polypeptide CD63).The inventors have unexpectedly realized that using extracellularvesicles (such as exosomes) as delivery vehicles for therapeuticpolypeptide decoy receptors (e.g. biopharmaceuticals) results not onlyin enhanced pharmacokinetics but unexpectedly also increases theefficacy of the therapeutic polypeptide decoy receptors, possibly as aresult of regenerative effects exerted by exosomes and other vesiclesper se. Additionally, employing extracellular vesicles as deliveryvectors for therapeutic polypeptides does not only facilitate productionin comparison with classical biologics, but the fact that each deliveryvesicle potentially comprises a considerable plurality of therapeuticconstructs (which in turn may comprise a plurality of therapeuticpolypeptide decoy receptors) potentially leads to a receptormultivalency that enhances the therapeutic efficacy and improvestreatment outcomes.

In preferred embodiments, the at least one therapeutic polypeptide decoyreceptor may be partially or completely devoid of its signalling domain,to make it signalling-incompetent. This may be achieved either viatruncating or mutating the polynucleotide encoding the signallingdomain, or via completely removing said polynucleotide, in order toblock any signalling from the therapeutic polypeptide decoy receptor. Ina further embodiment, the signalling domain of therapeutic polypeptidedecoy receptor may be partially or completely replaced by the carrierpolypeptide, to possibly minimize the size of the polypeptide construct.

The inventors have realized that it is, surprisingly, in some instancespreferable to utilize therapeutic polypeptide decoy receptors that aresignalling-incompetent, in order to avoid generating signals thatotherwise may negatively impact the therapeutic efficacy.

In one embodiment as per the present invention, the carrier polypeptidemay be located partially inside the therapeutic delivery vesicle and/orpartially in the therapeutic delivery vesicle membrane and/or partiallyoutside the therapeutic delivery vesicle. In a preferable embodiment,the carrier polypeptide is present substantially on the inside of thedelivery vesicle or in its membrane, whereas the therapeutic polypeptidedecoy receptor is present at least partially on the outside of thedelivery vesicle, to be able to exert its therapeutic effect. Thus, thepolypeptide construct may preferably be present in transmembrane form(i.e. a transmembrane polypeptide construct), with the carrierpolypeptide present substantially on the inside or in the vesicularmembrane and the therapeutic polypeptide decoy receptor presentsubstantially on the outside of the delivery vesicle (and either thecarrier polypeptide and/or the therapeutic polypeptide decoy receptorextending through the membrane of the delivery vesicle). In oneembodiment, more than one carrier polypeptide may be used, in order toimprove the expression of the therapeutic polypeptide decoy receptor onthe surface (outside) of the therapeutic delivery vesicle.

The location of the carrier polypeptide in the membrane may varydepending on the application and the therapeutic polypeptide inquestion; with the primary consideration being that the therapeuticpolypeptide decoy receptor is capable of interacting with itsinteraction partner, normally a circulating ligand, which is normallypresent extracellularly for instance in the blood or in any other bodilyfluid or on a circulating target cell. In further embodiments, the atleast one therapeutic polypeptide decoy receptor may be fused to thecarrier polypeptide via a chemical bond selected from the groupcomprising a peptide (amide) bond, a thio-ether bond, a di-sulfidebridge, and a biotin-streptavidin interaction. The formation of apeptide (amide) bond may naturally be achieved via recombinanttechnology (i.e. via expression of a suitable polynucleotide in a cellcapable of producing suitable delivery vesicles) but such a bond mayalso be generated using various conjugation strategies commonly employedwithin the art, for instance EDC/NHS-mediated conjugation, sulfo-NHSconjugation, or any other type of amide (peptide) conjugation approach.However, other methodologies for coupling the at least one therapeuticpolypeptide decoy receptor and the at least one carrier polypeptide maycomprise forming a disulfide bridge between e.g. two cysteine residues,or utilizing the natural interaction between biotin and streptavidin toconnect the therapeutic polypeptide decoy receptor and the carrierpolypeptide. An alternative to using fusion constructs and chemical bondformation is to place a lipid tag on the therapeutic polypeptide decoyreceptor and non-covalently coat the surface of the delivery vesiclewith the therapeutic polypeptide decoy receptor by means of simple lipidintercalation. Such lipid tags may include cholestoryl, stearyl,di-stearyl, myristoyl, palmitoyl, decanoyl, and other suitable lipidsknow to a person skilled in the art.

The carrier polypeptide may be selected from the group comprisingLamp2b, CD63, syndecan, synaptotagmin, ALIX (CHAMP 4) domain,ALIX-syntenin binding domain, ESCRT-proteins, PDGF, syntenin-PDZ, P6-and P9-domain, CD81, CD9, and any combination thereof. Again, theprimary consideration behind selecting an appropriate carrierpolypeptide pertains to its ability to efficiently carry the therapeuticpolypeptide decoy receptor to an appropriate vesicular location(normally its surface, or at least to a part of the therapeutic deliveryvesicle membrane that enables the therapeutic polypeptide decoyreceptors to interact with and bind to the ligand, i.e. its interactionpartner, to exert its therapeutic effect). Further in accordance withthe present invention, the carrier polypeptide may comprise thecytoplasmic part of syndecan. The cytoplasmic part of syndecan has aPDZ-binding domain which binds the syntenin-ALIX complex, and theSyntenin-ALIX complex subsequently forms an extracellular vesicle and/oran exosome (the PDZ domain would therefore essentially guide thereceptor to the extracellular vesicle).

The at least one therapeutic polypeptide decoy receptor as per thepresent invention may be selected from the group comprising receptors,for example, from the following receptor families: insulin, PDGF (SEQ IDNo 15-16), FGF (SEQ ID No 36-39), EGF, NGF (SEQ ID No 32), VEGF, HGF,TRK, EPH, AXL, LTK, TIE, ROR, DDR, RET, KLG, RYK, MuSK, Type I and TypeII TGF (SEQ ID No 33-35), activin, and TNF, PTCH1 (SEQ ID No 44),interleukins (IL) 1, 6, 12, 17, 23, and others (SEQ ID No 1-11),angiopoetin, HER phage display peptides binding ligands for thereceptors above (and possibly also phage display towards receptors inorder to occupy binding space via allosteric hindrance), 7-TM receptors,integrins, selectins (e.g. selectins E, P, and L (SEQ ID No 19-21),ligands of integrins/selectins membrane-bound antibodies, T-cellreceptors, NK-cell receptors, Toll-like receptors, PAMP, etc.

Also, engineered receptors that bind several ligands such as both VEGFand angiopoetin (DAAP) are in accordance with the present invention, andfurther all of the above-mentioned receptor families and specificreceptors are in line with the present invention. Further in accordancewith the present invention, the polypeptide construct attached totherapeutic delivery vesicles may comprise more than one therapeuticpolypeptide decoy receptor, and also more than one carrier polypeptide,in order to optimize e.g. the therapeutic effects or the transport ofthe therapeutic polypeptide decoy receptor to delivery vesicle membrane(or its surface).

The polypeptide construct as per the present invention may consequentlybe formed from any combination of the at least one therapeuticpolypeptide decoy receptor and the at least one carrier polypeptide.Exemplary embodiments comprise, for instance, (i) at least onetherapeutic polypeptide decoy receptor from the TNF family (e.g. TNFR1)combined with a carrier polypeptide selected from CD63 (SEQ ID No 14),Lamp2b, syndecan, synaptotagmin, or any other suitable carrierpolypeptide capable of transporting the at least one therapeuticpolypeptide decoy receptor to the surface (or essentially any suitablelocation on a therapeutic delivery vesicle), (ii) at least onetherapeutic polypeptide decoy receptor from the VEGF family (forinstance VEGFR) combined with a carrier polypeptide selected from CD63,Lamp2b, syndecan, synaptotagmin, or any other suitable carrierpolypeptide capable of transporting the at least one therapeuticpolypeptide decoy receptor to the surface (or essentially any suitablelocation on a therapeutic delivery vesicle), (iii) at least onetherapeutic polypeptide decoy receptor from the FGF family combined witha carrier polypeptide selected from CD63, Lamp2b, syndecan,synaptotagmin, or any other suitable carrier polypeptide capable oftransporting the at least one therapeutic polypeptide decoy receptor tothe surface (or essentially any suitable location on a therapeuticdelivery vesicle), (iv) at least one therapeutic polypeptide decoyreceptor from the EGF family combined with a carrier polypeptideselected from CD63, Lamp2b, syndecan, synaptotagmin, or any othersuitable carrier polypeptide capable of transporting the at least onetherapeutic polypeptide decoy receptor to the surface (or essentiallyany suitable location on a therapeutic delivery vesicle), (v) at leastone therapeutic polypeptide decoy receptor from the activin familycombined with a carrier polypeptide selected from CD63, Lamp2b,syndecan, synaptotagmin, (vi) at least one therapeutic polypeptide decoyreceptor from the interleukin receptor family (e.g. IL6R (SEQ ID No 1)or IL12R beta 1 (SEQ ID No 4) or IL1R Type 1 (SEQ ID No 3)) combinedwith a carrier polypeptide selected from e.g. CD63, Lamp2b, syndecan,synaptotagmin, or any other suitable carrier polypeptide capable oftransporting the at least one therapeutic polypeptide decoy receptor tothe surface (or essentially any suitable location on a therapeuticdelivery vesicle), or any other suitable carrier polypeptide capable oftransporting the at least one therapeutic polypeptide decoy receptor tothe surface (or essentially any suitable location on a therapeuticdelivery vesicle).

In yet another advantageous embodiment of the present invention, asuitable carrier polypeptide (such as CD63, Lamp2b, CD9, CD81,synaptotagmin, or syndecan, etc.) is fused to PTCH1, creating apolypeptide construct capable of sequestering sonic hedgehog (SHH),which is an important signalling molecule implicated in various cancers.The inventors have experimentally seen decreased tumour burden in micetreated with exosomes comprising various carrier polypeptides coupled toPTCH1 and to a specifically selected SHH-binding domain of PTCH1. Forinstance, in the experimental setup reported in FIG. 4 , exosomescomprising polypeptide constructs comprising CD63 or Lamp2b as thecarrier polypeptide and PTCH1 as the therapeutic polypeptide decoyreceptor showed similar anti-tumour efficacy as the syndecan-VEGFRconstructs shown in the graph in question.

In additional embodiments, the therapeutic delivery vesicle inaccordance with the present invention may further comprise at least onetargeting entity present. Said targeting entity is normally at leastpartially present on the outside of the delivery vesicle, in order toenable targeting of the vesicles to tissues, cell types, or organs ofinterest, e.g. to increase the concentration of delivery vesicleslocally at the site where the therapeutic efficacy needs to be as highas possible. The targeting entity may be a peptide or a polypeptide(e.g. an antibody or an antibody fragment), but it may also be a smallmolecule (such as a vitamin), a carbohydrate, a nucleic acid (such as anaptamer), or any other type of molecule that may confer targetingproperties to therapeutic delivery vesicles.

Further in accordance with the present invention, the therapeuticdelivery vesicle may be selected from the group comprising exosomes,microvesicles, apoptotic bodies, microparticles, ectosomes, prostatosomecardiosomes, liposomes, lipid-like materials or structures, lipidoids,VLDL particles, LDL particles, HDL particles, chylomicrons, etc.

Generally, the present invention pertains to delivery vesicles as perthe instant invention for use in medicine, and more specifically thepresent invention relates to the use in the prophylaxis and/oralleviation and/or treatment of diseases and disorders selected from thegroup comprising Crohn's disease, ulcerative colitis, rheumatoidarthritis, multiple sclerosis, systemic lupus erythematosus,sarcoidosis, idiopathic pulmonary fibrosis, psoriasis, tumor necrosisfactor (TNF) receptor-associated periodic syndrome (TRAPS), deficiencyof the interleukin-1 receptor antagonist (DIRA), endometriosis,autoimmune hepatitis, scleroderma, myositis, stroke, acute spinal cordinjury, vasculitis, Guillain-Barré syndrome, acute myocardialinfarction, ARDS, sepsis, meningitis, encephalitis, liver failure,kidney failure, graft-vs-host disease, Duschenne muscular dystrophy andother muscle diseases, neurodegenerative disease including Alzheimer'sdisease, Parkinson's disease, Huntingtons disease, ALS, cancer-inducedcachexia, anorexia, diabetes mellitus type 2, and cancers (for instancecancers sensitive to EGF,

VEGF, FGF). Some of the cancer types of relevance for the presentinvention comprises, for instance, Acute lymphoblastic leukemia (ALL),Acute myeloid leukemia, Adrenocortical carcinoma, AIDS-related cancers,AIDS-related lymphoma, Anal cancer, Appendix cancer, Astrocytoma,cerebellar or cerebral, Basal-cell carcinoma, Bile duct cancer, Bladdercancer, Bone tumor, Brainstem glioma, Brain cancer, Brain tumor(cerebellar astrocytoma, cerebral astrocytoma/malignant glioma,ependymoma, medulloblastoma, supratentorial primitive neuroectodermaltumors, visual pathway and hypothalamic glioma), Breast cancer,Bronchial adenomas/carcinoids, Burkitt's lymphoma, Carcinoid tumor(childhood, gastrointestinal), Carcinoma of unknown primary, Centralnervous system lymphoma, Cerebellar astrocytoma/Malignant glioma,Cervical cancer, Chronic lymphocytic leukemia, Chronic myelogenousleukemia, Chronic myeloproliferative disorders, Colon Cancer, CutaneousT-cell lymphoma, Desmoplastic small round cell tumor, Endometrialcancer, Ependymoma, Esophageal cancer, Extracranial germ cell tumor,Extragonadal Germ cell tumor, Extrahepatic bile duct cancer, Eye Cancer(Intraocular melanoma, Retinoblastoma), Gallbladder cancer, Gastric(Stomach) cancer, Gastrointestinal Carcinoid Tumor, Gastrointestinalstromal tumor (GIST), Germ cell tumor (extracranial, extragonadal, orovarian), Gestational trophoblastic tumor, Glioma (glioma of the brainstem, Cerebral Astrocytoma, Visual Pathway and Hypothalamic glioma),Gastric carcinoid, Hairy cell leukemia, Head and neck cancer, Heartcancer, Hepatocellular (liver) cancer, Hodgkin lymphoma, Hypopharyngealcancer, Intraocular Melanoma, Islet Cell Carcinoma (Endocrine Pancreas),Kaposi sarcoma, Kidney cancer (renal cell cancer), Laryngeal Cancer,Leukemias ((acute lymphoblastic (also called acute lymphocyticleukemia), acute myeloid (also called acute myelogenous leukemia),chronic lymphocytic (also called chronic lymphocytic leukemia), chronicmyelogenous (also called chronic myeloid leukemia), hairy cellleukemia)), Lip and Oral, Cavity Cancer, Liposarcoma, Liver Cancer(Primary), Lung Cancer (Non-Small Cell, Small Cell), Lymphomas((AIDS-related lymphoma, Burkitt lymphoma, cutaneous T-Cell lymphoma,Hodgkin lymphoma, Non-Hodgkin (an old classification of all lymphomasexcept Hodgkin's) lymphoma, Primary Central Nervous System lymphoma)),Medulloblastoma, Merkel Cell Carcinoma, Mesothelioma, MetastaticSquamous Neck Cancer with Occult Primary, Mouth Cancer, MultipleEndocrine Neoplasia Syndrome, Multiple Myeloma/Plasma Cell Neoplasm,Mycosis Fungoides, Myelodysplastic/Myeloproliferative Diseases,Myelogenous Leukemia, Chronic Myeloid Leukemia (Acute, Chronic),Myeloma, Nasal cavity and paranasal sinus cancer, Nasopharyngealcarcinoma, Neuroblastoma, Oral Cancer, Oropharyngeal cancer,Osteosarcoma/malignant fibrous histiocytoma of bone, Ovarian cancer,Ovarian epithelial cancer (Surface epithelial-stromal tumor), Ovariangerm cell tumor, Ovarian low malignant potential tumor, Pancreaticcancer, Pancreatic islet cell cancer, Parathyroid cancer, Penile cancer,Pharyngeal cancer, Pheochromocytoma, Pineal astrocytoma, Pinealgerminoma, Pineoblastoma and supratentorial primitive neuroectodermaltumors, Pituitary adenoma, Pleuropulmonary blastoma, Prostate cancer,Rectal cancer, Renal cell carcinoma (kidney cancer), Retinoblastoma,Rhabdomyosarcoma, Salivary gland cancer, Sarcoma (Ewing family of tumorssarcoma, Kaposi sarcoma, soft tissue sarcoma, uterine sarcoma), Sézarysyndrome, Skin cancer (nonmelanoma, melanoma), Small intestine cancer,Squamous cell, Squamous neck cancer, Stomach cancer, Supratentorialprimitive neuroectodermal tumor, Testicular cancer, Throat cancer,Thymoma and Thymic carcinoma, Thyroid cancer, Transitional cell cancerof the renal pelvis and ureter, Urethral cancer, Uterine cancer, Uterinesarcoma, Vaginal cancer, Vulvar cancer, Waldenström macroglobulinemia,and/or Wilm's tumor (kidney cancer).

Furthermore, the present invention pertains to pharmaceuticalcompositions comprising therapeutic delivery vesicles as per the presentinvention, normally formulated with at least one pharmaceuticallyacceptable excipient. The at least one pharmaceutically acceptableexcipient may be selected from the group comprising any pharmaceuticallyacceptable material, composition or vehicle, for instance a solid orliquid filler, a diluent, an excipient, a carrier, a solvent or anencapsulating material, which may be involved in e.g. suspending,maintaining the activity of or carrying or transporting the therapeuticdelivery vesicles from one organ, or portion of the body, to anotherorgan, or portion of the body (e.g. from the blood to any tissue and/ororgan and/or body part of interest).

The present invention also relates to cosmetic applications of thedelivery vesicles, either with or without the polypeptide construct(s).Thus, embodiments of the present invention may pertain to skin careproducts such as creams, lotions, gels, emulsions, ointments, pastes,powders, liniments, sunscreens, shampoos, etc., comprising the deliveryvesicles, in order to improve and/or alleviate symptoms and problemssuch as dry skin, wrinkles, folds, ridges, and/or skin creases. Thedelivery vesicles may exhibit beneficial effects without the polypeptideconstruct being present but the presence of a suitable polypeptideconstruct may further enhance the cosmetic efficacy. In one embodiment,the delivery vesicles as per the present invention may comprise abotulinum toxin (e.g. botox, for instance botulinum toxin types A-G) asthe therapeutic polypeptide decoy receptor (botulinum toxins may notnecessarily be used only for cosmetic applications but could also beapplied for e.g. treatment of migraine headaches and dystonia). In apreferred embodiment, exosomes from a suitable exosome-producing cellare comprised in a cosmetic cream, lotion, or gel for use in thetreatment (which is normally for cosmetic purposes) of wrinkles, lines,folds, ridges and/or skin creases.

In a further embodiment, the exosomes in accordance with the presentinvention may comprise a therapeutic polypeptide construct but may alsobe devoid of any artificially introduced therapeutic polypeptideconstruct or may contain polypeptide constructs having merely e.g.cosmetic capacity. Both extracellular vesicles devoid of therapeuticpolypeptide constructs and extracellular vesicles comprising therapeuticpolypeptide construct may mediate anti-inflammatory, anti-apoptotic andcell proliferative effects that may enhance wound healing and skinregeneration. Experiments carried out using (i) exosomes without anytherapeutic polypeptide construct and (ii) exosomes comprising a VEGFR1therapeutic polypeptide construct (with either CD63 or Lamp2b as thecarrier polypeptide) show that both strategies display strong cosmeticpotency in alleviating e.g. telangiectasias (small dilated blood vesselslocated near the skin). Exosomes devoid of therapeutic polypeptides werealso shown to alleviate cosmetic problems such as dry skin, wrinkles,rashes, etc., and additionally exosomes comprising e.g. TNFR-containingtherapeutic polypeptides are highly potent in treating rashes, scaling,and potentially psoriasis and psoriasis-related problems.

In further embodiments, the delivery vesicles in accordance with thepresent invention may comprise therapeutic polypeptide decoy receptorssuch as collagen, laminins (for instance laminins 111, 211, 511, and/or521), and/or cell-penetrating peptides (CPPs).

Optionally, glycosaminoglycans (GAGs) and/or other types ofcarbohydrates may be included in the delivery vesicles, to furtheraugment effects related to maintaining the structural integrity of theskin.

In one aspect as per the present invention, the polypeptide constructmay comprise a polypeptide construct which comprises virtually anytherapeutic polypeptide decoy receptor that can bind to a circulatingligand fused to virtually any carrier polypeptide.

The pharmaceutical compositions as per the present invention arenaturally suitable for use in medicine, and specifically in theprophylaxis and/or alleviation and/or treatment of diseases anddisorders selected from the group comprising Crohn's disease, ulcerativecolitis, rheumatoid arthritis, multiple sclerosis, systemic lupuserythematosus, sarcoidosis, idiopathic pulmonary fibrosis, psoriasis,tumour necrosis factor (TNF) receptor-associated periodic syndrome(TRAPS), deficiency of the interleukin-1 receptor antagonist (DIRA),endometriosis, autoimmune hepatitis, scleroderma, myositis, stroke,acute spinal cord injury, vasculitis, Guillain-Barré syndrome, acutemyocardial infarction, ARDS, sepsis, meningitis, encephalitis, liverfailure, kidney failure, graft-vs-host disease, Duschenne musculardystrophy and other muscle diseases, cancer-induced cachexia, anorexia,diabetes mellitus type 2, and cancer (for instance cancers sensitive toEGF, VEGF, FGF).

The therapeutic delivery vesicles as per the present invention may beadministered to a human or animal subject via various different routes,for instance auricular (otic), buccal, conjunctival, cutaneous, dental,electro-osmosis, endocervical, endosinusial, endotracheal, enteral,epidural, extra-amniotic, extracorporeal, hemodialysis, infiltration,interstitial, intra-abdominal, intra-amniotic, intra-arterial,intra-articular, intrabiliary, intrabronchial, intrabursal,intracardiac, intracartilaginous, intracaudal, intracavernous,intracavitary, intracerebral, intracisternal, intracorneal, intracoronal(dental), intracoronary, intracorporus cavernosum, intradermal,intradiscal, intraductal, intraduodenal, intradural, intraepidermal,intraesophageal, intragastric, intragingival, intraileal, intralesional,intraluminal, intralymphatic, intramedullary, intrameningeal,intramuscular, intraocular, intraovarian, intrapericardial,intraperitoneal, intrapleural, intraprostatic, intrapulmonary,intrasinal, intraspinal, intrasynovial, intratendinous, intratesticular,intrathecal, intrathoracic, intratubular, intratumor, intratympanic,intrauterine, intravascular, intravenous, intravenous bolus, intravenousdrip, intraventricular, intravesical, intravitreal, iontophoresis,irrigation, laryngeal, nasal, nasogastric, occlusive dressing technique,ophthalmic, oral, oropharyngeal, other, parenteral, percutaneous,periarticular, peridural, perineural, periodontal, rectal, respiratory(inhalation), retrobulbar, soft tissue, subarachnoid, subconjunctival,subcutaneous, sublingual, submucosal, topical, transdermal,transmucosal, transplacental, transtracheal, transtympanic, ureteral,urethral, and/or vaginal administration, and/or any combination of theabove administration routes.

In a further aspect, the present invention relates to a method ofproducing a therapeutic delivery vesicle, comprising the steps of (i)providing at least one polynucleotide construct encoding at least onepolypeptide construct, wherein the polypeptide construct comprises atleast one carrier polypeptide fused to at least one therapeuticpolypeptide decoy receptor that binds a circulating ligand, (ii)introducing said at least one polynucleotide construct into a cellcapable of producing suitable delivery vesicles (through translating thepolynucleotide construct into the corresponding polypeptide construct),and, (iii) collecting at least one delivery vesicle produced by the cellof step (ii). The method may further comprise a purification step,wherein the therapeutic delivery vesicle is purified through a procedureselected from the group comprising liquid chromatography (LC),high-performance liquid chromatography (HPLC), spin filtration,tangential flow filtration, centrifugation, immunoprecipitation, etc, orany combination thereof.

The inventors have surprisingly realized that applying a sequentialcombination of filtration (preferably ultrafiltration (UF)) and sizeexclusion liquid chromatography (LC) results in optimized purification,which in turn leads to superior therapeutic efficacy. Further, ascompared to ultracentrifugation (UC), which is routinely employed forpurifying exosomes, sequential ultrafiltration-liquid chromatography(UF-LC) is considerable faster and possible to scale to highermanufacturing volumes, which is a significant drawback of current UCmethodology. However, as will be described in greater details below, themost advantageous implication of the use of UF-LC instead of UC is thefact that exosomes (and other extracellular vesicles to which UF-LC isapplied) retain their biophysical and biological properties, whichresults in less accumulation in lung tissue upon in vivo administrationand therefore improves the therapeutic efficacy.

According to electron microscopy (EM) analysis, vesicles from both UFand UC preparations displayed a rounded or cup-shaped morphology. Inmost cases the vesicle diameter was measured to be around 100 nm, andthis was in accordance with results obtained via nanoparticle trackinganalysis (NTA). Of note however, a fraction of vesicles in the UC samplewas clearly distorted (either disrupted or fused to form slightly largervesicles) and such vesicles were not observed in UF samples. Hence,these results indicate that the UC methodology had a negative impact onvesicular integrity.

To verify the presence of vesicle aggregates in UC samples, theinventors next examined HEK293T CD63-EGFP labeled exosomes directly byfluorescence microscopy. Similar to the FCS results, only UC samplesdisplayed visible large aggregates in the fluorescence channel, whichwere not seen with UF samples. This was corroborated using thefluorescent dye DiOC6 labeled exosomes. Thus the UF isolation methodresults in preservation of the inherent biophysical properties ofvesicles compared to UC, which results in fusion/aggregation anddisruption of vesicles.

The UF experiments in accordance with the present invention wereperformed primarily using filters with a molecular weight cut-off of100-kDa, 250-kDa, and/or 500-kDa, or any sequential combination thereof.In preferred embodiments, 100-kDa cut-off is preferable but given thenumber of biomolecules with higher molecular weight, it is possible thatmedia/cell-secreted components other than exosomes are entrapped in thefilters and the UF protocol was therefore refined further using highlyunconventional size exclusion liquid chromatography. UF samples wereloaded on inter alia a Sephacryl S-300 or a Sephacryl S-500 sizeexclusion LC column where two distinct fractions were collected based onthe UV flow cell absorbance at 280 nm. NTA revealed that 98% of theparticles were recovered in fraction 1 where the mode particle size wasconsistent in all three UF-LC replicates. Subsequent total proteinstaining on SDS-PAGE confirmed that many of the contaminating proteinsoriginally seen in the UF sample were eluted in fraction 2 whilefraction 1 did not have any detectable levels of protein. By usingWestern Blot (WB), exosomal markers such as Alix and CD9 were onlydetected in fraction 1 and not in fraction 2, indicating that fraction 1contained pure exosomes. Moreover, the vesicle recovery rate followingLC fractionation was 70+/−19%, hence LC did not hamper the gain inparticle yield achieved by UF alone. WB corroborated this data, as theexosomal markers were more strongly expressed in LC fraction 1 comparedto UC-purified samples. Furthermore, the protein per vesicle ratio wasmuch lower for UF-LC compared to UC samples. EM was also performed onfraction 1 and 2, where intact cup-shaped vesicles were detected only infraction 1, while protein aggregates were seen in fraction 2.Furthermore, when HEK293T CD63-EGFP labeled exosomes purified with UF-LCwere visualized by fluorescent microscopy, EGFP positive vesiclesappeared similar to the UF purified vesicles indicating that LC did notaffect the biophysical properties of the vesicles. Thus, the inventorshave discovered that using a two-step method combining UF withsubsequent LC surprisingly allows for highly efficient isolation of highyields of biophysically intact exosomes free of protein contamination.The exosomes field currently relies completely on the perceivedeffectiveness of the UC method, which the present inventors have provedto be highly unreliable.

The UF-LC purification method of the present invention and theconventional UC method isolated vesicles with similar protein contents,as evidenced by the good proteomic overlap between the two methods.However, importantly, the UF-LC method results in high yieldpurification of vesicles devoid of non-exosomal contamination.

Despite similar proteomic profiles of exosomes isolated by the UF-LCmethod of the present invention and conventional UC methods, theinventors hypothesized that the distinct differences in exosomeintegrity between the purification methods (vesicle aggregation andfusion following UC purification) might influence their biologicalproperties in vivo. Given that it is well-established that aggregatedparticles typically show lung accumulation following intravenous (IV)injection the inventors speculated that UC purified exosomes mightpreferentially distribute to lung tissues compared to UF-LC purifiedvesicles. To investigate this, the same number of near-infraredfluorescent dye (DiR) labeled exosomes (based on NTA calculations) wereinjected via the tail vein in adult Balb/c mice and the biodistributionwas analysed using IVIS imaging 24 h post injection. As postulated, UCpurified exosomes showed a 4.6 times (p<0.0001) stronger signal in thelungs compared to UF-LC purified vesicles. The signal from the liver wasas expected higher in the UF-LC group (p<0.0001), since the totalfluorescence injected only differed by 6%. Thus vesicles isolated usingthe highly advantageous UF-LC methods of the present invention arebiophysically intact, do not preferentially accumulate in lung andtherefore are better suited for in vivo therapeutic applications.

As can be realized from the above description, the UF-LC method isgenerally applicable to purification of any type of vesicles (such asexosomes, liposomes, etc.) and may be in a broad aspect compriseexposing any type of suitable vesicle preparation which needs to bepurified to UF-LC as described herein. In one exemplary embodiment, thepresent invention thus pertains to obtaining extracellular vesicles froma suitable source (for instance vesicle produced by the methods of thepresent invention, which may optionally comprise polypeptide constructswhich in turn comprise carrier polypeptides and therapeutic decoyreceptors), exposing the vesicles (which are normally present in amedium also comprising various other components such as proteins andpeptides) to an ultrafiltration step followed by a size exclusion liquidchromatography (LC) step.

Further, in a preferred embodiment the present invention relates to amethod of producing a therapeutic delivery vesicle, comprising the stepsof (i) providing at least one polynucleotide construct encoding at leastone polypeptide construct, wherein the polypeptide construct comprisesat least one carrier polypeptide fused to at least one therapeuticpolypeptide decoy receptor that binds a circulating ligand, (ii)introducing said at least one polynucleotide construct into a cellcapable of producing suitable delivery vesicles (through translating thepolynucleotide construct into the corresponding polypeptide construct),and, (iii) purifying the delivery vesicles of step (ii) usingultrafiltration (UF) followed by size exclusion liquid chromatography(LC). The delivery vesicles obtained using said methodology maytherefore display significantly enhanced biophysical stability andbiological properties than vesicles obtained via conventional UCmethodology. In a further embodiment, at least one filter may be usedfor the UF step, and the filter(s) may have the same or differentcut-offs, e.g. one could initially perform a first step with a cut-offof 100 kDa and in a second step a filter with a cut-off of 200 kDa.Naturally, the filter may be selected to have any appropriate cut-off,for instance 100 kDa, 200 kDa, 500 kDa, etc. Furthermore, in additionalembodiments, the column used for the LC step may have essentially anysuitable pore size. S-300, S-500 and S-1000 of a Sephacryl column workedequally well, consistently producing two well-defined peaks with one ofsaid peaks being the vesicle-containing fraction.

In a further embodiment of the present invention, the production ofextracellular vesicles (such as exosomes) may be increased by includingautophagy inhibitors in the cell culture medium when growing thevesicle-producing cells. As portrayed in FIG. 8 , treating cells withautophagy inhibitors resulted in a surprising increase of the exosomalyield. Various substances can be used to inhibit the different stages ofthe autophagy pathway, for instance including but not limited toBafilomycin A and chloroquine (inhibiting the fusion of theautophagosome with the lysosome), and/or 3-methyladenine (which is aPI3K inhibitor that hinders the formation of pre-stages of theautophagosome). Thus, the present invention further relates to the useof autophagy inhibitors to increase the vesicle yield in cell culture.Autophagy-inhibiting substances as per the present invention may includebeclin-1 inhibitors, PI3K inhibitors (e.g. 3-methyladenine), andinhibitors of the fusion between autophagosome and lysosome (e.g.Bafilomycin A and chloroquine). Thus, in one general aspect, the presentinvention relates to increasing the yield of extracellular vesicles bytreating the vesicle-producing cell(s) with at least one inhibitor ofautophagy.

In a preferred embodiment, the method of producing a therapeuticdelivery vesicle as the present invention may hence comprise the stepsof (i) providing at least one polynucleotide construct encoding at leastone polypeptide construct, (ii) introducing said at least onepolynucleotide construct into a cell capable of producing vesiclescomprising the polypeptide construct translated from the polynucleotideconstruct, (iii) cultivating said cells in the presence of at least oneautophagy inhibitor, (iv) purifying the delivery vesicles obtained fromsaid cells using UF-LC purification.

The method of producing a therapeutic delivery vesicle may alternativelycomprise the steps of (i) providing (a) at least one polynucleotideconstruct encoding at least one therapeutic polypeptide decoy receptor,and (b) at least one polynucleotide construct encoding at least onecarrier polypeptide, (ii) introducing at least one of the polynucleotideconstruct (a) and at least one of the polynucleotide construct (b) intoa cell capable of producing delivery vesicles, and (iii) collecting atleast one delivery vesicle produced by the cell of step (ii). Whenemploying this method, the at least one therapeutic polypeptide decoyreceptor and the at least one carrier polypeptide may form a singlepolypeptide construct through formation of e.g. a disulfide bridgebetween the carrier polypeptide and the therapeutic polypeptide decoyreceptor, or through the formation of a biotin-streptavidin interaction,or through the formation of any other type of chemical bond, includingthe formation of a syndecan-syntenin-ALIX complex

In yet another aspect, the present invention pertains to a polypeptideconstruct comprising at least one therapeutic polypeptide decoy receptorthat binds a target molecule, fused to at least one carrier polypeptide.Said polypeptide construct may in exemplary embodiments comprise, forinstance, (i) at least one therapeutic polypeptide decoy receptor fromthe TNF family combined with a carrier polypeptide selected from CD63,Lamp2b, syndecan, synaptotagmin (or any derivatives or analoguesthereof), or any other suitable carrier polypeptide capable oftransporting the at least one therapeutic polypeptide decoy receptor tothe surface (or essentially any suitable location on a therapeuticdelivery vesicle), (ii) at least one therapeutic polypeptide decoyreceptor from the VEGF family combined with a carrier polypeptideselected from CD63, Lamp2b, syndecan, synaptotagmin (or any derivativesor analogues thereof), or any other suitable carrier polypeptide capableof transporting the at least one therapeutic polypeptide decoy receptorto the surface (or essentially any suitable location on a therapeuticdelivery vesicle), (iii) at least one therapeutic polypeptide decoyreceptor from the FGF family combined with a carrier polypeptideselected from CD63, Lamp2b, syndecan, synaptotagmin (or any derivativesor analogues thereof), or any other suitable carrier polypeptide capableof transporting the at least one therapeutic polypeptide decoy receptorto the surface (or essentially any suitable location on a therapeuticdelivery vesicle), (iv) at least one therapeutic polypeptide decoyreceptor from the EGF family combined with a carrier polypeptideselected from CD63, Lamp2b, syndecan, synaptotagmin (or any derivativesor analogues thereof), or any other suitable carrier polypeptide capableof transporting the at least one therapeutic polypeptide decoy receptorto the surface (or essentially any suitable location on a therapeuticdelivery vesicle), (v) at least one therapeutic polypeptide decoyreceptor from the activin family combined with a carrier polypeptideselected from CD63, Lamp2b, syndecan, synaptotagmin (or any derivativesor analogues thereof), or any other suitable carrier polypeptide capableof transporting the at least one therapeutic polypeptide decoy receptorto the surface (or essentially any suitable location on a therapeuticdelivery vesicle).

Moreover, the present invention may in further aspects relate to apolynucleotide construct encoding at least one therapeutic polypeptidein accordance with the present invention, and, in an additional aspect,a cell comprising at least one polynucleotide construct and/or at leastone polypeptide construct. In a further aspect, the present inventionpertains to a therapeutic delivery vesicle obtainable by the methods asper the present invention. The cells that may be utilized for thepurposes of the present invention comprise for instance mesenchymalcells, adult stem cells (eg. myoblasts), induced pluripotent stem (iPS)cells, cord blood stem cells, embryonic stem cells, and/or amniotic stemcells, blood-derived cells (eg. B-cells, macrophages, DC-cells, T-cells,NK-cells, platelets etc), immortalized eukaryotic cells or cell-lines(eg. neuroblastoma cells NSC34, N2a and SHSY5Y, HEK cells, C17.2neuronal stem cells, bEND3 neuroendothelial cells, HeLa cells, U2OScells etc), or any combination of these sources of cells.

The inventors have unexpectedly realized that the proteome ofextracellular vesicles obtainable from cells exposed to stress-inducingculturing conditions (such as serum-starvation and oxygen deprivation)is enhanced in positive GO terms as compared to the proteome ofextracellular vesicles from cells grown under normal control conditions.Extracellular vesicles (such as exosomes) from cells exposed toserum-starvation and/or oxygen deprivation (i.e. reduced oxygen supply)were analysed with state of the art LC/MS/MS (proteomics) to examine thechanges in proteome the different culturing conditions bring about.Surprisingly, stress-inducing conditions enriched anti-apoptotic andmetabolically active proteins to a greater extent than normal culturingconditions according to GO-terms (FIG. 10 ) (GO-terms: translation,metabolic processes, glycolysis and ribosomal proteins). Hence,serum-starvation and/or oxygen deprivation enrich proteins for survivaland metabolic processes in the exosomes, which would be a benefit forregenerative purposes. The GO-terms were normalized to the proteome ofexosomes from a reference control cell and the enrichment is expressedas fold increase over the expected value from the reference cell. Thus,in a further generally applicable aspect, the present invention relatesto the use of stress-inducing conditions to enrich the proteome of anextracellular vesicle (e.g. an exosomes) for metabolically activeproteins and/or anti-apoptotic proteins, i.e. positive GO terms such astranslation, metabolic processes, glycolysis and/or ribosomal proteins.In a further embodiment, the method for obtaining extracellular deliveryvesicles as according to the present invention may comprise a step wherethe cells from which the extracellular vesicles are obtained are exposedto stress-inducing conditions (for instance but not limited to oxygendeprivation and/or serum-starvation), in order to induce enrichment ofmetabolically active proteins and/or anti-apoptotic proteins to enhancethe regenerative effects of the extracellular vesicles. When comparingcontrol vesicles (without any therapeutic polypeptide) cultured understress-inducing conditions with control vesicles (without anytherapeutic polypeptide) cultured under normal conditions thestress-exposed extracellular vesicles generate a clearly enhancedtherapeutic effect in various inflammatory models, indicating that theregenerative capabilities of the extracellular vesicles (notablyexosomes) have increased due to the stress-inducing culturingconditions.

A particularly advantageous aspect of the present invention pertains toexposing cells from which extracellular vesicles are to be obtained to acombination of both autophagy inhibitors and stress-inducing conditions,in order to (1) increase the yield of vesicles and (2) increase theregenerative capacity of the exosomes thus produced. Vesicles (such asexosomes) obtained via this combinatorial approach may be purified usingthe advantageous UF-LC protocol of the present invention, to trulyensure that the therapeutic efficacy of the extracellular vesicles isoptimized.

Further, the present invention relates to a method of treatmentcomprising administering a therapeutically effective amount oftherapeutic delivery vesicles to a subject in need thereof, wherein themethod is aimed at improving, alleviating, and/or preventing diseasessuch as Crohn's disease, ulcerative colitis, rheumatoid arthritis,multiple sclerosis, systemic lupus erythematosus, sarcoidosis,idiopathic pulmonary fibrosis, psoriasis, tumor necrosis factor (TNF)receptor-associated periodic syndrome (TRAPS), deficiency of theinterleukin-1 receptor antagonist (DIRA), endometriosis, autoimmunehepatitis, scleroderma, myositis, stroke, acute spinal cord injury,vasculitis, Guillain-Barré syndrome, acute myocardial infarction, ARDS,sepsis, meningitis, encephalitis, liver failure, kidney failure,graft-vs-host disease, Duschenne muscular dystrophy and other musclediseases, neurodegenerative disease including Alzheimer's disease,Parkinson's diease, Huntingtons disease, cancer-induced cachexia,anorexia, diabetes mellitus type 2, and cancers (for instance cancerssensitive to EGF, VEGF, FGF). Some of the cancer types of relevance forthe present invention comprises, for instance, Acute lymphoblasticleukemia (ALL), Acute myeloid leukemia, Adrenocortical carcinoma,AIDS-related cancers, AIDS-related lymphoma, Anal cancer, Appendixcancer, Astrocytoma, cerebellar or cerebral, Basal-cell carcinoma, Bileduct cancer, Bladder cancer, Bone tumor, Brainstem glioma, Brain cancer,Brain tumor (cerebellar astrocytoma, cerebral astrocytoma/malignantglioma, ependymoma, medulloblastoma, supratentorial primitiveneuroectodermal tumors, visual pathway and hypothalamic glioma), Breastcancer, Bronchial adenomas/carcinoids, Burkitt's lymphoma, Carcinoidtumor (childhood, gastrointestinal), Carcinoma of unknown primary,Central nervous system lymphoma, Cerebellar astrocytoma/Malignantglioma, Cervical cancer, Chronic lymphocytic leukemia, Chronicmyelogenous leukemia, Chronic myeloproliferative disorders, ColonCancer, Cutaneous T-cell lymphoma, Desmoplastic small round cell tumor,Endometrial cancer, Ependymoma, Esophageal cancer, Extracranial germcell tumor, Extragonadal Germ cell tumor, Extrahepatic bile duct cancer,Eye Cancer (Intraocular melanoma, Retinoblastoma), Gallbladder cancer,Gastric (Stomach) cancer, Gastrointestinal Carcinoid Tumor,Gastrointestinal stromal tumor (GIST), Germ cell tumor (extracranial,extragonadal, or ovarian), Gestational trophoblastic tumor, Glioma(glioma of the brain stem, Cerebral Astrocytoma, Visual Pathway andHypothalamic glioma), Gastric carcinoid, Hairy cell leukemia, Head andneck cancer, Heart cancer, Hepatocellular (liver) cancer, Hodgkinlymphoma, Hypopharyngeal cancer, Intraocular Melanoma, Islet CellCarcinoma (Endocrine Pancreas), Kaposi sarcoma, Kidney cancer (renalcell cancer), Laryngeal Cancer, Leukemias ((acute lymphoblastic (alsocalled acute lymphocytic leukemia), acute myeloid (also called acutemyelogenous leukemia), chronic lymphocytic (also called chroniclymphocytic leukemia), chronic myelogenous (also called chronic myeloidleukemia), hairy cell leukemia)), Lip and Oral, Cavity Cancer,Liposarcoma, Liver Cancer (Primary), Lung Cancer (Non-Small Cell, SmallCell), Lymphomas ((AIDS-related lymphoma, Burkitt lymphoma, cutaneousT-Cell lymphoma, Hodgkin lymphoma, Non-Hodgkin (an old classification ofall lymphomas except Hodgkin's) lymphoma, Primary Central Nervous Systemlymphoma)), Medulloblastoma, Merkel Cell Carcinoma, Mesothelioma,Metastatic Squamous Neck Cancer with Occult Primary, Mouth Cancer,Multiple Endocrine Neoplasia Syndrome, Multiple Myeloma/Plasma CellNeoplasm, Mycosis Fungoides, Myelodysplastic/MyeloproliferativeDiseases, Myelogenous Leukemia, Chronic Myeloid Leukemia (Acute,Chronic), Myeloma, Nasal cavity and paranasal sinus cancer,Nasopharyngeal carcinoma, Neuroblastoma, Oral Cancer, Oropharyngealcancer, Osteosarcoma/malignant fibrous histiocytoma of bone, Ovariancancer, Ovarian epithelial cancer (Surface epithelial-stromal tumor),Ovarian germ cell tumor, Ovarian low malignant potential tumor,Pancreatic cancer, Pancreatic islet cell cancer, Parathyroid cancer,Penile cancer, Pharyngeal cancer, Pheochromocytoma, Pineal astrocytoma,Pineal germinoma, Pineoblastoma and supratentorial primitiveneuroectodermal tumors, Pituitary adenoma, Pleuropulmonary blastoma,Prostate cancer, Rectal cancer, Renal cell carcinoma (kidney cancer),Retinoblastoma, Rhabdomyosarcoma, Salivary gland cancer, Sarcoma (Ewingfamily of tumors sarcoma, Kaposi sarcoma, soft tissue sarcoma, uterinesarcoma), Sézary syndrome, Skin cancer (nonmelanoma, melanoma), Smallintestine cancer, Squamous cell, Squamous neck cancer, Stomach cancer,Supratentorial primitive neuroectodermal tumor, Testicular cancer,Throat cancer, Thymoma and Thymic carcinoma, Thyroid cancer,Transitional cell cancer of the renal pelvis and ureter, Urethralcancer, Uterine cancer, Uterine sarcoma, Vaginal cancer, Vulvar cancer,Waldenström macroglobulinemia, and/or Wilm's tumor (kidney cancer).

Unlike many other therapies, exosomes and other extracellular vesicleshave the potential to cross the blood-brain barrier (BBB). Therapeuticdelivery exosomes comprising signalling-incompetent decoy receptors fore.g. IL6, IL-1β and TNFα may thus modulate the various disorders of thecentral nervous system (CNS), and specifically various forms ofneuro-inflammation. Neuro-inflammation is inflammation of the nervoussystem, including the central nervous system (CNS). Theneuroinflammation may be acute, e.g. infection or traumatic events, orchronic, e.g. neurodegenerative diseases (including Alzheimer's disease,Parkinsons disease and demyelinating diseases, such as multiplesclerosis (MS)). In the CNS, glial cells, including microglia andastrocytes, have an important role in innate immunity. These cells,among others cell types in the brain, can produce cytokines andchemokines that act as neuro-modulators. The most common cytokines inCNS neuro-inflammation include IL6, IL-1β and TNFα. Production of thesespro-inflammatory cytokines can cause neurotoxicity and may compromisethe integrity of the blood-brain-barrier (BBB).

In an in vivo model of experimental autoimmune encephalomyelitis (EAE),mice treated with therapeutic delivery exosomes comprising varioustherapeutic polypeptide decoy receptor(s) (as described above) displayeda markedly improved disease phenotype, as illustrated by FIG. 9 . Thus,in a further aspect, the present invention pertains to delivery of anysuitable receptor (for instance IL-6R, TNFR1, IL-1βR, and/or anycombination thereof) to the CNS, to treat essentially anyneuro-inflammation.

Furthermore, the instant invention additionally relates to reagents,kits, cell mediums, and cell culturing processes. For instance, cellculturing processes utilizing the methods for producing the therapeuticdelivery vesicles of the present invention may be employed in a varietyof suitable exosome-producing cell lines, such as mesenchymal cells,adult stem cells (e.g. myoblasts), induced pluripotent stem (iPS) cells,cord blood stem cells, embryonic stem cells, and/or amniotic stem cells,blood-derived cells (eg. B-cells, macrophages, DC cells, T-cells,NK-cells, platelets etc), immortalized eukaryotic cells or cell-lines(eg. neuroblastoma cells NSC34, N2a and SHSY5Y, HEK cells, C17.2neuronal stem cells, bEND3 neuroendothelial cells, HeLa cells, U2OScells etc), or any combination of these sources of cells. In furtherembodiments, the present invention pertains to cell culture medium, anysuitable reagent for in vitro use, and/or a kit of parts comprising thetherapeutic delivery vesicles. Particularly advantageous kits maycomprise, optionally in separate contains, cell media for culturingvesicle-producing cells and autophagy inhibitors, to increase thevesicle (preferably exosome) production yield. The cell culture media asper the present invention may be tailored to contain very little or noserum in order to ensure that the vesicles produced by the cells areexpressing higher amounts of metabolically active and anti-apoptoticproteins, to increase their inherent regenerative capacity. Forinstance, in one preferred embodiment the present invention pertains toa kit comprising (i) culturing media for cell culture underserum-starvation conditions to enhance the regenerative effects of theextracellular vesicles (exosomes) produced, (ii) autophagy inhibitorssuch as chloroquine, bafilomycin A, and/or 3-methyladenine, or anycombination thereof to increase the production yield of theextracellular vesicles (exosomes), and suitable cells for production ofextracellular vesicles, for instance exosomes.

It shall be understood that the above described exemplifying aspects,embodiments, and alternatives, and variants can be modified withoutdeparting from the scope of the invention, inter alia with respect tothe described constituents and components (e.g. the therapeutic deliveryvesicles, the therapeutic polypeptide decoy receptors, and the carrierpolypeptides, etc.), materials (e.g. therapeutic delivery vesicles, celltypes, etc.), and method parameters (e.g. purification techniques,conjugation approaches, etc.) applied. The invention will now be furtherexemplified with the enclosed examples, which naturally also can bemodified without departing from the scope of the invention.

EXAMPLES Cell-Based Delivery Vesicle Production

A cell type producing a suitable therapeutic delivery vesicle, such asan exosome, a microvesicle, or any other type of cell-derived structure,is plated/seeded with an appropriate density in cell media. In the caseof exosome production, an exosome-producing cell type is plated/seededwith an appropriate density in cell media. The cell media is removedafter 24 hours and the plate is washed with PBS 3 times. New freshexosome-depleted media or serum free media is added. Exosomes arepurified from the conditioned media. The time of incubation before themedia is taken from the cells usually ranges from 48-72 hours dependingon cell type, it may however be increased or decreased under certaincircumstances.

The media that the cells are grown in is always depleted of foreignexosomes and microparticles by ultracentrifugation at 110 000 governight before incubation with the cells. Alternatively, a serum freemedia is applied in its place, such as OptiMEM or DMEM.

The conditioned media can be purified with different techniques;ultrafiltration with sequential LC or high performance liquidchromatography purification, ultra-centrifugation, or commerciallyavailable kits. Before ultra-filtration or ultracentrifugation, theconditioned media is cleared of cells and cell debris by spinning themedia at 300 g for 5 minutes. The supernatant is subsequently spun againat 1500 g for 15 minutes and ran through a 0.2-micrometer filter. Theconditioned media is thus cleared of vesicles and aggregates over 200nanometer in size. The 0.2-micrometer filtration can be exchanged to a15 000 g spin for 30 minutes.

By ultra-filtration or tangential flow the conditioned media isconcentrated. The MWCO limit is in both methods used are 100 kDa. Theconcentrated media is further purified by LC or HPLC, using a suitablecolumn, such as Sephacryl S-300. The first fraction from the LC/HPLCcontains the exosomes.

By ultracentrifugation the conditioned media is spun at 110 000 g for 70minutes, the supernatant is discarded and the pellet is re-suspended inPBS and once again centrifuged at 110 000 g for 70 minutes. Thesupernatant is discarded and the pellet re-suspended in PBS. To furtherpurify the exosomes the second step of the purification process can bedone with a 30% sucrose cushion. The cushion traps the exosomes. Theexosomes are eluted from the sucrose cushion by another centrifugationstep in PBS at 110 000 g for 70 minutes and then the pellet isre-suspended in PBS.

The exosome sample can be analyzed with western blot, ELISA, NTA andelectron microscopy. The amount of decoy receptors in each sample may bedetermined by ELISA towards a polypeptide of interest. The dose given isthen calculated as amount of polypeptide given from the concentrationobtained from the ELISA.

Artificial Vesicle Production

Liposomes, lipid-like structures, lipidoids, and other types ofartificially produced lipid-based delivery vesicles may also be utilizedfor the purposes of the present invention. These vesicles may beproduced by techniques known in the art and the polypeptide constructcomprising the carrier polypeptide and the therapeutic polypeptide decoyreceptor may be loaded onto the vesicles using standard technology, forinstance lipid-tagging, etc.

Validation of UF-LC Purification Protocol Cell Culture

NSC-34, a fusion of motor neuron enriched embryonic mouse spinal cordcells with mouse neuroblastoma, N2a, a mouse neuroblastoma cell line,B16F10, a mouse melanoma cell line and human embryonic kidney (HEK293T)cells were cultured at 37° C. with 5% CO₂ in complete media comprised ofDulbecco's Modified Eagle Medium (DMEM, Invitrogen), supplemented with10% fetal bovine serum (FBS, Cellgro), and penicillin/streptomycin(pen/strep, 5000 μg/ml, Cellgro). For exosome isolation, media werechanged 24 h after seeding to either pre-spun media or OptiMEM. Pre-spunmedia is DMEM supplemented with 10% FBS that had been pre-spun at120,000 g for 70 min prior to making up the vesicle devoid media. BothOptiMEM and pre-spun media were supplemented with pen/strep. Conditionedmedia was then collected for exosome isolation 48 h after incubation.For large-scale experiments, conditioned media collected from multipleflasks were pooled prior to isolation of exosomes.

Transfection of HEK293T Cells

6 million cells were seeded one day prior to transfection in a 15 cmculture dish with DMEM complete media. Transfection of the CD63-EGFPplasmid was done using polyethyleneimine (PEI) at a 1:4 pDNA:PEI ratio.Briefly, 25 μg of plasmid and 100 μg of PEI were diluted in 500 μl ofOptiMEM in separate tubes. After 5 min of incubation at room temperature(RT), the pDNA and PEI solutions were combined and incubated for afurther 30 min at RT to form the DNA/PEI complexes. The complexes werethen added dropwise to cells. After 4 h, the cell growth mediacontaining the complexes was removed; the cells were washed withphosphate buffer saline (PBS) and fresh OptiMEM, supplemented with P/Santibiotics was added on the cells. After 48 h of incubation, theconditioned media was collected for exosome isolation.

Ultracentrifugation (UC) for Isolation of Exosomes

Isolation of exosomes by UC was performed. Briefly, protocol 1 involvestwo low speed spins, 300 g for 5 min followed by 1200 g for 10 min toget rid of cell debris and larger particles. The supernatant wassubsequently filtered through a 0.22 μm syringe filter before the finalultracentrifugation step at 120,000 g for 70 min. Protocol 2 followsthat of protocol 1 but includes an additional PBS wash at 120,000 g for70 min. Briefly, conditioned media was subjected to an initial low speedspin at 300 g for 5 min, followed by a 10,000 g spin for 30 min. Thesupernatant was then ultracentrifuged at 120,000 g for 70 min. Protocol4 is similar to protocol 1 but lacks the 0.22 μm syringe filtrationstep.

Ultrafiltration (UF) for Isolation of Exosomes

The UF protocol involves the same initial low-speed spins as that of theUC protocol. Instead of a high-speed ultracentrifugation at the finalstep, the cell culture supernatants were spun in 100-kDa cut-off AmiconUltra-15 spin filter (Millipore) while placental perfusates were spun in300-kDa cut-off filter (Vivaspin, Sartorius Stedim) at 3500 g for 15min. PBS was then added to the filters and spun down to wash thesamples.

Liquid Chromatography Fractionation of UF Samples (UF-LC) from CellCulture

UF samples, prepared as described above, were loaded onto a HiPrep 16/60Sephacryl S-300 HR column for samples collected from OptiMEM conditionedmedia and a 26/60 S-500 HR column for samples collected from pre-spunconditioned media (GE Healthcare), connected to an ÄKTA prime (GEhealthcare) equipped with a UV flow cell. Each individual fraction wascollected according to the UV absorbance. The collected fractions werethen concentrated using a 30-kDa cut-off Amicon Ultra-15 spin filter(Millipore) to 300-400 μl and stored in −80° C. until further analyses.

Liquid Chromatography Fraction of UF Samples (UF-LC) from PlacentalPerfusions

1 ml of the UF STBM sample was loaded onto an XK16/70 Sephacryl S-1000column (GE Healthcare), connected to fraction collector (RediFrac,Pharmacia). A pump speed of 2 ml/min was used and 4 ml fractions werecollected. The collected fractions were then concentrated on a 30-kDaspin filter (Vivaspin, Sartorius Stedim), diluted to 300-400 μl andstored in −80° C. until further analysis.

Western Blotting

Western blotting was performed using either the Bio-Rad® Mini-PROTEAN®Tetra cell or the iBlot® system (Invitrogen, Life Technologies)according to the manufacturer's instructions. To cross-compare the yieldof exosomes, we proceeded to load equal volumes of the re-suspendedexosome pellet or filtrate on the gel.

For the Bio-Rad system, 15 μl of exosome samples with 15 μl of 2×Laemilli sample buffer (Bio-Rad) containing 5% β-mercaptoethanol weremixed and heated at 100° C. for 10 min. Samples were then loaded in a1.5 mm, 10% Tris/Glycine SDS-polyacrylamide gel and ran at 170 V for60-70 min in running buffer, until the dye front reached the bottom ofthe tank. Proteins on the gel were then transferred to a polyvinylidinefluoride (PVDF) membrane (Millipore) at 100 V for 60-70 min in transferbuffer containing 20% methanol. Membranes were then incubated inblocking buffer (5% fat-free milk in Tris buffer saline with 0.1%Tween-20 (TBS-T) for 60 min at room temperature (RT) with gentleshaking.

For the iBlot® system, 30 μl of sample was mixed with a sample buffer,containing 0.5 M ditiothreitol (DTT), 0.4 M sodium carbonate (Na₂CO₃),8% SDS and 10% glycerol, and heated at 65° C. for 5 min. Samples werethen loaded in a NuPAGE® Novex® 4-12% Bis-Tris Gel and ran at 120 V inrunning buffer until the dye front reached the bottom of the gel. Theproteins on the gel were transferred to an iBlot nitrocellulose membrane(Invitrogen) for 7 min with the iBlot system. Membranes were stainedwith Ponceau S dye that was later washed away with PBS before blockingwith Odyssey blocking buffer for 60 min at RT with gentle shaking.

After the blocking step, the membrane was incubated with freshlyprepared primary antibody solution (anti-CD9, anti-PDC6I (Alix),anti-Tsg101 and anti-calnexin; all at 1:1,000 dilution from Abcam,Cambridge UK) overnight at 4° C. or 2 h at RT. Membranes were washedthree times, 10 min each using washing buffer (TBS-T) with vigorousshaking before adding the secondary antibody solution (anti-mouse IgGDyLight-800 at 1:10,000 dilution if detecting Alix; anti-rabbit IgGDyLight-800 at 1:10,000 dilution for detecting CD9, Tsg101 and Calnexin)and incubated for 1 h at RT. After the secondary antibody incubation,membranes were washed three times, 10 min each and visualised byscanning both 700- and 800-nm channels on the LI-COR Odyssey CLxinfrared imaging system. For subsequent probing of other proteins on thesame membrane, the membrane was washed three times, 10 min each beforere-incubation with the next primary antibody.

Nanoparticle Tracking Analysis

For particle size determination, nanoparticle tracking analysis (NTA)was performed with a NanoSight NS500 instrument equipped with the NTA2.3 analytical software. For all our recordings, we used a camera levelof 13 or 15 and automatic function for all post-acquisition settings:blur and minimum expected particle size, except in the detectionthreshold where we fixed it at 5. Samples were thawed on ice and dilutedin PBS between 1:500 to 1:20,000 to achieve a particle count of between2×10⁸ and 2×10⁹ per mL. Once the dilution of the sample was determined,sample was loaded in the sample chamber and the camera focus wasadjusted to make the particles appear as sharp dots of light. Using thescript control function, we recorded five 30 or 60 s videos for eachsample; incorporating a sample advance and 5 s delay between eachrecording. For GFP positive exosomes the same set up was used with oneminor alteration, which was that the sample was under constant flow inthe sample chamber not to bleach the GFP signal. These measurements werethen analysed using the batch process function and results were exportedto Microsoft Excel for further analysis.

Quantification of Proteins and RNA in Exosomes

Protein quantities in exosomes were quantified using the microBCA assaykit (Thermo Scientific) and levels of RNA were measured using theQuant-iT™ RiboGreen® RNA assay kit (Life Technologies), according to themanufacturer's instructions.

Electron Microscopy

5 μl of exosome suspension was diluted 1:1 with PBS and added onformvar-carbon coated electron microscopy grids for 20 min. The grid wasblotted with filter paper and 15 μl of 2% uranyl acetate (UA) was addedon the grid for 1 min. Next, UA was removed and 15 μl of distilled waterwas added for 1 min. The water droplet was then removed and the grid wasleft to air dry for 15 min. The grids were then visualized in theelectron microscope.

Fluorescence Microscopy

CD63-EGFP positive exosomes were generated as described above. Theparticles were quantified by NTA and the UF-LC and UC samples werediluted to the same concentration of particles/ml. Before anymeasurements the exosomes were re-suspended with a 27G needle. Thesamples were positioned on a microscope slide and covered with acoverslip and analysed Microscopy was performed using Olympus IX-81inverted microscope (Olympus America, Center Valley Pa., USA) equippedwith 20× objective. The following fluorescence filter-set (ChromaTechnology Corp., Bellows Falls, Vt., USA) was used, with the centralwavelength and bandwidth of the excitation and emission filters asindicated: GFP (Ex. 470/40 nm; Em. 525/50 nm)

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) of Exosomes

Exosomes from UC and UF-LC were concentrated by speedvac and lysed with1% SDS, 25 mM HEPES, 1 mM DTT. Lysates were heated to 95° C. for 5 minfollowed by sonication for 1 min and centrifugation at 14,000 g for 15min. The supernatant was mixed with 1 mM DTT, 8 M urea, 25 mM HEPES, pH7.6 and transferred to a 10-kDa cut-off centrifugation filtering unit(Pall, Nanosep®), and centrifuged at 14,000 g for 15 min, followed by anaddition of the 8 M urea buffer and centrifugation again. Proteins werealkylated by 50 mM iodoacetamide (IAA) in 8 M urea, 25 mM HEPES for 10min, The proteins were then centrifuged at 14,000 g for 15 min followedby 2 more additions and centrifugations with 8 M urea, 25 mM HEPES.Trypsin (Promega) in 250 mM urea, 50 mM HEPES was added to the celllysate at a ratio of 1:50 trypsin:protein and incubated overnight at 37°C. The filter units were centrifuged at 14,000 g for 15 min followed byanother centrifugation with MQ and the flow-through was collected.Peptides were cleaned by a strata-X-C-cartridge (Phenomenex).

Before analysis on the Q Exactive (Thermo Fischer Scientific, San Jose,Calif., USA), peptides were separated using an Agilent 1200 nano-LCsystem. Samples were trapped on a Zorbax 300SB-C18, and separated on aNTCC-360/100-5-153 (Nikkyo Technos., Ltd) column using a gradient of A(3% ACN, 0.1% FA) and B (95% ACN, 0.1% FA), ranging from 7% to 40% B in240 min with a flow of 0.4 μl/min. The Q Exactive was operated in a datadependent manner, selecting top 5 precursors for fragmentation by HCD.The survey scan was performed at 70,000 resolution from 300-1700 m/z,using lock mass at m/z 445.120025, with a max injection time of 100 msand target of 1×10⁶ ions. For generation of HCD fragmentation spectra, amax ion injection time of 500 ms and AGC of 1×10⁵ were used beforefragmentation at 30% normalized collision energy, 17,500 resolution.Precursors were isolated with a width of 2 m/z and put on the exclusionlist for 70 s. Single and unassigned charge states were rejected fromprecursor selection.

Proteome discoverer 1.3 with sequest-percolator was used for proteinidentification. Precursor mass tolerance was set to 10 ppm and forfragments to 0.02 Da. Oxidized methionine and was set as dynamicmodification, and carbamidomethylation as static modification. Spectrawere matched to a combined mus musculus and bos taurus ensembl 72database, and results were filtered to 1% FDR. Identifications in bostaurus was considered to originate from FBS and removed. GO termenrichment analysis was done using Panther.

Exosome Biodistribution in Mice

Conditioned cell supernatants were filtered through a 0.22 μm syringefilter and incubated with 1 μM DiR(1,1′-Dioctadecyl-3,3,3′,3′-Tetramethylindotricarbocyanine Iodide)(Invitrogen). The conditioned media with DiR was then ultracentrifugedat 110,000 g for 70 min or concentrated with a 100 kDa Amicon Ultra spinfilter (Millipore). The UC pellet was re-suspended and spun again in PBSto purify away-unbound DiR or LC fractionated as described above. Thepurified exosomes were quantified with NTA and equal amounts ofparticles from both UC and LC preparations were injected in the tailvein of Balb/c mice (n=5). 24 h post injection, the organs wereharvested and subjected to imaging in the In Vivo Imaging System (IVIS)Spectrum (Caliper). The IVIS was set to record the fluorescence for 2seconds (excitation 710, emission 760) and the data obtained was thenanalysed with the IVIS software. All animal experiments were approved byThe Swedish Local Board for Laboratory Animals. The experiments wereperformed in accordance with the ethical permission and designed tominimize the suffering and pain of the animals.

Colitis Treatment Using Exosomes Displaying Signalling-IncompetentCD63-sTNFR1

The well-studied TNBS-induced colitis model in mice was used, simulatingthe cytokine storm, the diarrhea, weight decrease, and gut inflammationseen in IBD patients. 24 mice were divided into four treatment groups,with 6 mice per group. The mice were pre-sensitized by applying 150 μlof a olive oil-acetate solution with 2% TNBS, on the skin, 1 week priorto colitis induction. Colitis was then induced by giving a rectalinfusion of 100 μl solution containing 1.5% TNBS in 40% ethanol.Immediately post colitis induction, 30 μg exosomes in 200 μl wereadministrated intravenously in the tail vein. The mice were given eitherdecoy signalling-incompetent TNFR1-CD63 exosomes, unmodified exosomes,signalling-competent TNFR1-CD63 exosomes, or PBS as mock treatment,depending on the assigned treatment group. The bodyweight was recordeddaily.

As can be seen from FIG. 2 , administration of exosomes comprising decoyreceptor as per the present invention leads to successful treatment ofcolitis in mice. The signalling-incompetent decoy exosomes successfullytreat induced colitis within a few days with less loss in body weight,whereas unmodified exosomes show a moderate effect. Signalling-competentdecoy receptors in fact aggravate the condition.

Western Blot of CD63-sTNFR1 on the Exosomal Surface

Western Blot was carried out towards the extracellular part of TNFR1, toverify the presence of the CD63-sTNFR1 polypeptide construct on theexosomal surface. Predicted molecular weight for the CD63-TNFR1construct is 38.52 kDa, which can be seen in the vicinity of the 37 kDareference band, both in the cell lysate sample and the exosome sample.The fusion protein is loaded onto the exosomes with great efficiency,since the band is so strong in the exosome fraction (the band around 15kDa is an irrelevant unspecific band).

Neutralization of TNFα-Mediated Toxicity

The neutralizing activity of signalling-incompetent CD63-TNFR1 exosomes,signalling-competent CD63-TNFR1 exosomes and exosomes from N2a cellsagainst human TNF-α was measured on the mouse WEHI 164 cell line treatedwith actinomycin D as previously described (Austgulen et al., 1986;Khabar et al., 1995), in order to verify the binding affinity for TNFα.Briefly, WHEI 164 cells were seeded in triplicate at 1×10⁴ cells/well ina 96-well plate and cultured in RPMI 1640 medium supplemented with 10%(v/v) FBS for 20 h. Subsequently, serially diluted exosomes (finalconcentration: 0.5-100 μg/ml) in the medium containing 2 μg/mlactinomycin D were added to the cell culture together with 0.1 ng/ml ofhuman TNF-α. The cells were incubated for an additional 20 h at atemperature of 37 degrees Centigrade and cell viability was analyzedusing a colorimetric MTT-based Cell Growth Determination kit (Sigma, St.Louis, Mo.). The ED₅₀ value was calculated by complex sigmoid non-linearregression analysis using Sigma plot software (Systat software, Inc.Richmond, Calif.).

Anti-Tumour Efficacy of Exosomes and Liposomes DisplayingSignalling-Incompetent Syndecan/CD63-sVEGFR1

30 mice were implanted with 1×10⁶ B16/F10 melanoma cells into the flankat day zero. The mice were then divided into five treatment groups, with6 mice per group. After one week (day 7), the mice received intravenousinjections of 30 μg exosomes in 200 μl which were repeated every seconddays for two weeks. The mice were given exosomes comprisingsignalling-incompetent syndecan-sVEGFR1, signalling-incompetentCD63-sVEGFR1 exosomes, unmodified exosomes, and exosomes comprisingsignalling-competent CD63-sVEGFR1, or PBS as mock treatment depending onassigned treatment group. The tumour volume was measured every secondday.

The arrow in FIG. 4 indicates start of treatment (day 7). The micetreated with signalling-incompetent decoy sVEGFR1 exosomes(syndecan-sVEGFR1 EXO and CD63-sVEGFR1 EXO) displayed the lowest tumourburden after treatment.

Treatment with unmodified exosomes had a moderate effect on tumour size,whereas treatment with exosomes comprising signalling-competentCD63-sVEGFR1 resulted in an aggravated condition, compared to themock-treated control group.

The above experiments were also repeated with liposomes comprising thesame set of polypeptide decoy receptors and similar results wereobtained.

Treatment of MDX Mice

N2a cells were seeded at 3 million per 150 cm² flask and grown in DMEMwith 10% FBS. After 24 hours the cells were PEI-transfected withplasmids encoding signalling-incompetent activin-syndecan orsignalling-incompetent activin-synaptotagmin. 4 hours post transfectionthe media was changed to OptiMEM. 72 hours after the media changeexosomes produced by the N2a cells were harvested by ultra-filtrationand sequential LC purification. The exosomes were used immediately orstored at −20. MDX mice were obtained from Charles River at a weight ofaround 18-19 grams. The mice were allocated into 4 groups with 6 mice ineach group. The mice received injections of exosomes or PBS twice weeklyfor 12 weeks. The weight was recorded before each injection.

FIG. 5 shows treatment efficacy in MDX mice of exosomes comprising thetherapeutic decoy polypeptide receptor activin fused to either thecarrier proteins syndecan (solid black line) or synaptotagmin(long-dashed grey line). Bi-weekly treatment with the above therapeuticdelivery exosomes resulted in a considerably greater body weightincrease than treatment with unmodified exosomes and mock treatment.

The above experiments were also repeated with chylomicrons and similarresults were obtained.

Treatment of Neuro-Inflammation

In an in vivo model of experimental autoimmune encephalomyelitis (EAE),mice treated with decoy exosomes (as described above) displayed amarkedly improved disease phenotype, FIG. 9 . EAE was induced byimmunization of mice with neuroantigen (myelin basic protein, MBP) andcomplete Freund's adjuvant (containing M. tuberculosis), followed byinjection of pertussis toxin to produce severe and reliable EAE. Diseaseprogression with clinical symptoms was recorded daily from disease onset(day 12-28). The symptoms are scored based on severity (0=normal mouse;no overt signs of disease; 1=limptail or hind limb weakness, but notboth; 2=limptail and hind limb weakness; 3=partial hind limb paralysis;4=complete hind limb paralysis; 5=moribund state; death by EAE:sacrifice for humane reasons), resulting in a mean clinical score usedto assess disease state. Notable is that mice, with and without inducedEAE, treated with exosomes derived from neural origin resulted in spasmsand subsequent death, compared to treatment of exosomes from other cellorigins where this phenomenon was not present. FIG. 9 illustrates theefficacy of the following delivery exosomes:

-   -   Decoy exosomes comprising IL6R+TNFR1    -   Decoy exosomes comprising IL6R    -   Decoy exosomes comprising TNFR1    -   Decoy exosomes comprising IL-1βR    -   Unmodified exosomes    -   Untreated control

As can be seen from FIG. 9 , EAE-mice treated with decoy exosomesdisplaying signalling-incompetent receptors for IL6, IL-1β and TNFαdisplay a very moderate disease manifestation compared to mock treatedcontrol, whereas mice treated with signalling-competent (TNFR1signalling-competent) therapeutic polypeptide receptor-containingexosome display a worsened disease.

What is claimed is:
 1. A method for purifying extracellular vesiclescomprising: (i) exposing a sample comprising at least one extracellularvesicle to ultrafiltration; and (ii) exposing the sample following theultrafiltration in step (i) to size exclusion liquid chromatography. 2.A method of claim 1, wherein at least one filter is used duringultrafiltration.
 3. A method of claim 2, wherein the at least one filtercomprises a molecular weight cut-off of 100 kDa.
 4. A method of claim 2,wherein the at least one filter comprises a molecular weight cut-off of200 kDa.
 5. A method of claim 2, wherein the at least one filtercomprises a molecular weight cut-off of 500 kDa.
 6. A method of claim 1,wherein at least two different filters are used during ultrafiltrationand wherein the at least two different filters have the same molecularweight cut-off.
 7. A method of claim 1, wherein at least two differentfilters are used during ultrafiltration and wherein the at least twodifferent filters have a different molecular weight cut-off.
 8. A methodof claim 1, further comprising prior to step (i) exposing the sample tostress-inducing conditions.
 9. A method of claim 8, wherein thestress-inducing conditions are oxygen deprivation, serum starvation, ora combination thereof.
 10. A method of claim 1, further comprising priorto step (i) exposing the sample to autophagy-inhibiting substances. 11.A method of claim 1, wherein the extracellular vesicles purified usingultrafiltration followed by size exclusion liquid chromatographycomprise less protein contamination than extracellular vesicles purifiedusing ultrafiltration alone.
 12. A method of claim 1, wherein theextracellular vesicles purified using ultrafiltration followed by sizeexclusion liquid chromatography comprise less vesicle distortion andimproved vesicle integrity than extracellular vesicles purified usingultrafiltration alone.
 13. A method for purifying extracellularvesicles, comprising: (i) introducing at least one polynucleotideconstruct encoding at least one polypeptide into a cell capable ofproducing extracellular vesicles; (ii) collecting the extracellularvesicles produced by the cell of step (i); and (iii) purifying theextracellular vesicles collected in step (ii) using ultrafiltrationfollowed by size exclusion liquid chromatography.
 14. A method of claim13, wherein at least one filter is used during ultrafiltration.
 15. Amethod of claim 14, wherein the at least one filter comprises amolecular weight cut-off of 100 kDa.
 16. A method of claim 14, whereinthe at least one filter comprises a molecular weight cut-off of 200 kDa.17. A method of claim 14, wherein the at least one filter comprises amolecular weight cut-off of 500 kDa.
 18. A method of claim 13, whereinat least two different filters are used during ultrafiltration andwherein the at least two different filters have the same molecularweight cut-off.
 19. A method of claim 13, wherein at least two differentfilters are used during ultrafiltration and wherein the at least twodifferent filters have a different molecular weight cut-off.
 20. Amethod of claim 13, further comprising prior to step (ii) exposing thecell to stress-inducing conditions.
 21. A method of claim 20, whereinthe stress-inducing conditions are oxygen deprivation, serum starvation,or a combination thereof.
 22. A method of claim 13, further comprisingprior to step (ii) exposing the cell to autophagy-inhibiting substances.23. A method of claim 13, wherein the extracellular vesicles purifiedusing ultrafiltration followed by size exclusion liquid chromatographycomprise less protein contamination than extracellular vesicles purifiedusing ultrafiltration alone.
 24. A method of claim 13, wherein theextracellular vesicles purified using ultrafiltration followed by sizeexclusion liquid chromatography comprise less vesicle distortion andimproved vesicle integrity than extracellular vesicles purified usingultrafiltration alone.